06 Melgar Surie adult rsv 508

Evidence to Recommendations Framework (EtR):
RSV Vaccination in Adults Aged 50 –59 years
Amadea Britton, MD, Co -Lead Adult RSV Vaccine Work Group
Michael Melgar, MD, Co -Lead Adult RSV Vaccine Work Group
Diya Surie, MD, Co -Lead Adult RSV Vaccine Work Group
Coronavirus and Other Respiratory Viruses Division (CORVD)
Advisory Committee on Immunization Practices (ACIP)
April 16, 2025National Center for Immunization and Respiratory Diseases
2•Should adults aged 50 –59 years at increased risk of severe RSV disease
be recommended to receive a single dose of RSV vaccination?Policy questions
3We plan to consider adults aged 18 –49 years at increased
risk of severe RSV disease at the June 2025 meeting.
4•ACIP Evidence to Recommendations Framework (cdc.gov)Evidence to Recommendations ( EtR) framework
EtR Domain Question(s)
Public Health Problem ▪Is the problem of public health importance?
Benefits and Harms ▪How substantial are the desirable anticipated effects?
▪How substantial are the undesirable anticipated effects?
▪Do the desirable effects outweigh the undesirable effects?
Values ▪Does the target population feel the desirable effects are large relative
to the undesirable effects?
▪Is there important uncertainty about, or variability in, how much
people value the main outcomes?
Acceptability ▪Is the intervention acceptable to key stakeholders?
Feasibility ▪Is the intervention feasible to implement?
Resource Use ▪Is the intervention a reasonable and efficient allocation of resources?
Equity ▪What would be the impact of the intervention on health equity?
EtRDomain: Public Health Problem
Is the problem of public health importance among adults aged 50 -59 years at
increased risk of severe RSV disease?
6•Population -based rates of RSV disease among adults aged 50 –59 years are
lower than those among older adultsWhat do we know about RSV epidemiology in adults aged
50–59 years?
7Estimated annual RSV -associated hospitalization rates per 100,000 adults*
aged ≥18 years by age group and year, RSV -NET, 2016 –17 to 2019 –20 and
2022 –23
0100200300400500600700
18–49 50–54 55–59 60–64 65–69 70–74 ≥75 Annual RSV -associated
hospitalizations per 100,000
population
Age group, years2016 –17
2017 –18
2018 –19
2019 –20
2022-23Surveillance
season:
Havers FP, et al. Burden of Respiratory Syncytial Virus –Associated Hospitalizations in US Adults, October 2016 to September 2023 . JAMA Netw  Open. 2024;7(11):e2444756. https://pmc.ncbi.nlm.nih.gov/articles/PMC11561688/
Hospitalization rates were adjusted for under -detection of RSV infection due to testing practices and diagnostic test sensitivit y. Season is defined as October to April for 2016 to 2017 through 2019 to 2020 and as October to
September for 2022 to 2023. Error bars represent 95% CIs.
*Estimated rates exclude recorded hospitalizations among pregnant women.Risk-based recommendationAge-based recommendation
8Estimated  annual number  of
RSV-associated
hospitalizations * among
adults aged ≥18 years by age
group and year, RSV -NET,
2016 –17 to 2019 –20, 2022 –23
0 20,000 40,000 60,000 80,000 100,000≥80 75–7970–7465–6960–6455–5950–5418–49
Annual RSV -associated hospitalizationsAge
group,
years2016 –17 2017 –18 2018 –19 2019 –20 2022 –23
Havers FP , et al. Burden of Respiratory Syncytial Virus -Associated
Hospitalizations in US Adults, October 2016 to September 2023. JAMA
Netw  Open. 2024 Nov 4;7(11):e2444756.
https://pubmed.ncbi.nlm.nih.gov/39535791/
*Estimated hospitalizations exclude recorded hospitalizations among
pregnant women.Estimated  15,000 –20,000
annual RSV -associated
hospitalizations  in
U.S. adults aged 50–59 yearsSurveillance
season:
9•Population -based rates of RSV disease among adults aged 50 –59 years are
lower than those among older adults
•However, we know that some younger adults are at increased risk of RSV
hospitalization, even if the risk in the general population is lowWhat do we know about RSV epidemiology in adults aged
50–59 years?
10Top 10 most common underlying medical conditions among
adults aged ≥50 years hospitalized with RSV are similar by age
Major medical condition categories
among persons aged 50–59 years
hospitalized with RSVWeighted
%
Cardiovascular disease 46.3
Diabetes mellitus 37.0
Asthma 29.7
COPD or chronic bronchitis 26.5
Immunocompromised condition 25.5
Severe obesity (BMI ≥40 kg/m2) 21.3
Chronic kidney disease 19.8
Neurologic disorder 19.4
Gastrointestinal, liver, or pancreatic
disease9.8
Blood disorder 4.5Major medical condition categories
among persons aged ≥60 years
hospitalized with RSVWeighted
%
Cardiovascular disease 66.7
Diabetes mellitus 36.9
COPD or chronic bronchitis 35.0
Chronic kidney disease 29.1
Neurologic disorder 26.5
Immunocompromised condition 18.5
Asthma 18.1
Severe obesity (BMI ≥40 kg/m2) 10.7
Gastrointestinal, liver, or pancreatic
disease6.5
Rheumatologic disease 4.2
BMI: body mass index; COPD: chronic obstructive pulmonary disease
Unpublished RSV -NET data, 2015 –2016 to 2017 –2018, 2022 –2023, and 2023 –2024
Categories are not mutually exclusive; individual patients may have underlying conditions in more than one category Slide credit: Dr. Monica Patton
11Unpublished data. Update on analysis from Woodruff et al. First presented to ACIP in February 2024: https://www.cdc.gov/acip/downloads/slides -2024 -02-28-29/03 -RSV-Adults -Woodruff -508.pdf
BMI: Body Mass Index (kg/m2), COPD: Chronic Obstructive Pulmonary Disease. Data are preliminary and unpublished. Current smoking is defined as smoking c igarettes every day or some days at the time of survey response.
Adjusted rate ratios and 95% confidence intervals are derived from Poisson regression using Monte Carlo simulation methods an d adjust for age, sex and race and ethnicity group. Error bars represent 95% confidence intervals.Adjusted Rate Ratios for RSV -Associated Hospitalization by Chronic
Condition among Community -Dwelling Adults Aged ≥50 Years
6.5
4.63.73.12.42.0 1.91.51.3
0.11.010.0100.0
Chronic
Kidney
DiseaseCOPD Severe
obesity
(BMI ≥40)Asthma Coronary
Artery
DiseaseDiabetes
mellitusCurrent
smokerStroke Obesity
(BMI 30-39)Adjusted rate ratio
12aRR (95% CI)1
Number of chronic conditions2
0 ref
1 2.1 (1.4, 3.2)
≥2 7.3 (5.0, 10.6)
Age group, years
50–59 ref
60–74 1.9 (1.3, 2.7)
≥75 6.0 (4.2, 8.6)
Race or ethnicity group
White, non -Hispanic ref
Black, non -Hispanic 1.1 (0.8, 1.5)
Other race or Hispanic ethnicity 1.7 (1.3, 2.5)
Sex
Male Ref
Female 1.3 (1.0, 1.6)
1 Adjusted rate ratios ( aRR) and 95% confidence intervals (CI) were estimated using
Poisson regression and Monte Carlo simulation. Adjusted for all covariates in table.
2 Includes history of asthma, chronic kidney disease, chronic obstructive pulmonary
disease, coronary artery disease, current smoker, diabetes, stroke, obesity (body mass
index [BMI] 30 –39 kg/m2) or severe obesity (BMI ≥40 kg/m2)Among community -dwelling
adults aged ≥50 years, a
history of ≥2 chronic
conditions  and age ≥75 years
were the strongest
independent  risk factors for
RSV-associated hospitalization.
Unpublished data. Update on analysis from Woodruff et al. First presented to ACIP in February 2024 : https://www.cdc.gov/acip/downloads/slides -2024 -02-28-29/03 -RSV-Adults -Woodruff -508.pdf
13RSV-associated hospitalization rates among community -dwelling adults
aged ≥50 years with chronic medical conditions, 2017 –2018 season
BMI: Body Mass Index (kg/m2), COPD: Chronic Obstructive Pulmonary Disease. Data are preliminary and unpublished. Rates of laboratory -confirmed RSV -associat ed hospitalization account for under -detection of RSV infection
among hospitalized adults and sensitivity of diagnostic tests. Poisson regression using Monte Carlo simulation estimated rate s and 95% confidence intervals (represented by error bars). Rates for community -dwelling adults
exclude residents of nursing homes and long -term care facilities and are not adjusted for sex or race and ethnicity group.0200400600
50–59
60–74
≥75
50–59
60–74
≥75
50–59
60–74
≥75
50–59
60–74
≥75
50–59
60–74
≥75
50–59
60–74
≥75
50–59
60–74
≥75
50–59
60–74
≥75
50–59
60–74
≥75
50–59
60–74
≥75
None of
These
ConditionsChronic
Kidney
DiseaseCOPD Severe
obesity
(BMI ≥40)Asthma Coronary
Artery
DiseaseDiabetes
mellitusStroke Obesity
(BMI 30 –
39)Current
smokerRSV-associated hospitalization rate
(per 100,000)
Community -dwelling adults
with none of these conditionsCommunity -dwelling adults
with each condition
////////
//////////////////
14RSV-associated hospitalization rates among community -dwelling adults
aged ≥50 years with chronic medical conditions, 2017 –2018 season
BMI: Body Mass Index (kg/m2), COPD: Chronic Obstructive Pulmonary Disease. Data are preliminary and unpublished. Rates of laboratory -confirmed RSV -associat ed hospitalization account for under -detection of RSV
infection among hospitalized adults and sensitivity of diagnostic tests. Poisson regression using Monte Carlo simulation esti mated rates and 95% confidence intervals (represented by error bars). Rates for community -
dwelling adults exclude residents of nursing homes and long -term care facilities and are not adjusted for sex or race and ethnic ity group.0200400600
50–59
60–74
≥75
50–59
60–74
≥75
50–59
60–74
≥75
50–59
60–74
≥75
50–59
60–74
≥75
50–59
60–74
≥75
50–59
60–74
≥75
50–59
60–74
≥75
50–59
60–74
≥75
50–59
60–74
≥75
None of
These
ConditionsChronic
Kidney
DiseaseCOPD Severe
obesity
(BMI ≥40)Asthma Coronary
Artery
DiseaseDiabetes
mellitusStroke Obesity
(BMI 30 –
39)Current
smokerRSV-associated hospitalization rate
(per 100,000)
Community -dwelling adults
with none of these conditionsCommunity -dwelling adults
with each condition
////////
//////////////////
15What do we know about conditions and risk factors not
included in the RSV -NET analysis?
1. Kujawski  SA, et al. Rates of respiratory syncytial virus (RSV) -associated hospitalization among adults with congestive heart failure -United States, 2015 -2017. PLoS  One. 2022 Mar 9;17(3):e0264890.
https://pubmed.ncbi.nlm.nih.gov/35263382/
2. Ison MG, Hirsch HH. Community -Acquired Respiratory Viruses in Transplant Patients: Diversity, Impact, Unmet Clinical Needs. Clin  Microbiol  Rev. 2019 Sep 11;32(4):e00042 -19. https://pubmed.ncbi.nlm.nih.gov/31511250/
3. Manuel O, Estabrook M; American Society of Transplantation Infectious Diseases Community of Practice. RNA respiratory viral i nfections in solid organ transplant recipients: Guidelines from the American Society of
Transplantation Infectious Diseases Community of Practice. Clin Transplant. 2019 Sep;33(9):e13511 https://pubmed.ncbi.nlm.nih.gov/30817023/
4. Waghmare A, et al. Supplemental Oxygen -Free Days in Hematopoietic Cell Transplant Recipients With Respiratory Syncytial Virus. J  Infect Dis. 2017 Dec 5;216(10):1235 -1244. https://pubmed.ncbi.nlm.nih.gov/28961971/
5. Martino R, et al. Prospective study of the incidence, clinical features, and outcome of symptomatic upper and lower respirato ry tract infections by respiratory viruses in adult recipients of hematopoietic stem cell transplants for
hematologic malignancies. Biol Blood Marrow Transplant. 2005 Oct;11(10):781 -96. https://pubmed.ncbi.nlm.nih.gov/16182179/
6. Sheshadri  A, et al. Pulmonary Impairment after Respiratory Viral Infections Is Associated with High Mortality in Allogeneic Hematopoiet ic Cell Transplant Recipients. Biol Blood Marrow Transplant. 2019 Apr;25(4):800 -809.
https://pubmed.ncbi.nlm.nih.gov/30521974/
7. Testaert  H, et al. Incidence, management and outcome of respiratory syncytial virus infection in adult lung transplant recipients: a 9 -year retrospective multicentre  study. Clin Microbiol  Infect. 2021 Jun;27(6):897 -903.
https://pubmed.ncbi.nlm.nih.gov/32827713/  ▪ Other medical conditions associated with increased risk of severe RSV disease
–Heart failure
•As many as 28%  of adults hospitalized with RSV infection have chronic heart failure1
•Among adults <65 years, hospitalization rates are >14x  higher in those with versus without
heart failure1
–Immune compromise
•Severe RSV disease and high RSV -associated mortality ( >20% ), especially among hematopoietic
cell transplant and lung transplant recipients2–4
•RSV may account for 20 –25% of symptomatic viral respiratory illness after hematopoietic cell
transplant5 and is associated with pulmonary impairment and mortality.6
•RSV infection is associated with increased risk of allograft dysfunction after lung transplant7
16•Population -based rates of RSV disease among adults aged 50 –59 years are
lower than those among older adults
•However, we know that some younger adults are at increased risk of RSV
hospitalization, even if the risk in the general population is low
•Adults aged 50 –59 years who are hospitalized with RSV have similar
underlying conditions as those in hospitalized adults ≥60 years, but more
often have asthma, immune compromise, and severe obesity
•Adults aged 50 –59 years with certain chronic conditions experience RSV
hospitalization rates similar to those in adults ≥75 years in whom age is the
only identified risk factor (who are recommended to receive RSV vaccination)
•Adults with heart failure and immune compromise more often experience
severe outcomes from RSV infectionPublic health problem: Evidence in adults aged 50 –59 years
17Prevalence of ≥1 chronic medical condition among adults aged 50-59 years is at least 31%  using a narrow
definition of chronic medical conditions* and may be as high as 43% when using a broad definition**
National Health and Nutrition Examination Survey (NHANES), 2015 –2018.
SOURCE: National Center for Health Statistics (NCHS), National Health and Nutrition Examination Survey (NHANES), 2015 –2018. All estimates are crude estimates with no age adjustment and age is age at interview. Error bars represent Korn and Graubard  95% confidence intervals. NHANES is representative of the civilian, non -institutionalized U.S. population. For
“narrow” definition: Severe obesity was defined as BMI ≥40 kg/m2. Diabetes with complication was defined as 1) having diabetes: self -reported diabetes, fasting plasma glucose ≥126 mg/dL, or he moglobin A1c ≥6.5%, AND 2) having one of the following complications of diabetes assessed within the survey: serious heart di sease as defined below, chronic kidney disease
(stage 3, 4, or 5) defined as estimated glomerular filtration rate (eGFR) ˂60 (stages 3 –5) further defined below, or having self -reported diabetes and having a doctor previously told them that diabetes affected their eyes or that they have retinopathy. O ther complications of diabetes are not included in this definition. Serious heart disease was defined based on self -report as
diagnosed congestive heart failure, coronary heart disease, angina, or heart attack, or angina grades 1 or 2 determined by th e Rose Angina Questionnaire. Asthma was defined as self -reporting ever being diagnosed with asthma and still having asthma. Chronic  kidney disease was defined as estimated glomerular filtration rate (eGFR) ˂30 (stages 4 –5), and using a forward
equation for adjustment of creatinine because of methods changes. eGFR calculated using the 2021 CKD -EPI creatinine equation (ht tps://www.nejm.org/doi/10.1056/NEJMoa2102953). Urine albumin is not included in this definition. Chronic obstructive pulmonar y disease (COPD) was defined as self -reported diagnosed COPD, emphysema, or current chronic bronchitis. Liver
condition was defined as self -reporting ever being diagnosed with any kind of liver condition and still having any kind of liver  condition. Having at least one of the above conditions for the narrow definition was defined based on the seven (7) condition s listed. For “broad” definition: conditions were defined identically except diabetes was defined as self -reported diabetes,
fasting plasma glucose ≥126 mg/dL, or hemoglobin A1c ≥6.5% without complication; chronic kidney disease was defined as estima ted glomerular filtration rate (eGFR) ˂60 (stages 3,4, or 5); and cancer or malignancy in past 2 years was added. This was define d as self -reporting having "ever been told by a doctor or other health professional that you had cancer or a
malignancy of any kind" and reporting age at diagnosis in years as being within 2 years of current age in years. As participa nt age and age at diagnosis for cancer or malignancy are top -coded for ages 80 years and above, those who are aged 80 years and abo ve and report having diagnosis at age 78 years or above are coded as having cancer or malignancy in the past 2 years;
this results in an inflated estimate. Of those with any history of cancer or malignancy ages 50 –79 years, 18.6% had a diagnosis within the past 2 years. Of those with any history of cancer or malignancy ages 80 years and above, 36.0% had a diagnosis at ≥ age 78 years. Having at least one of the above conditions for the broad definition was defined based on the eight (8)
conditions listed. Among the fasting sample, ~94% had complete data for all reported medical conditions, ~6% were missing dat a for one (1) medical condition, <1% were missing data for two (2) medical conditions, and none were missing data for three (3) or more medical conditions. Estimates of having ≥1 condition are weighted using fasting sample weight.  *Narrow definition , at least one of:
•Serious heart disease
•Diabetes with complication
•Chronic obstructive pulmonary disease
•Asthma
•Severe obesity (BMI ≥40 kg/m2)
•Liver condition
•Chronic kidney disease, stage 4 or 5
**Broad definition , as above, OR:
•Diabetes with or without  complication
•Chronic kidney disease, stage 3, 4, or 5
•Cancer or malignancy in past 2 years
BMI: body mass index313945 435771
0102030405060708090100
50–59 years 60–74 years 75 years and olderPrevalence of at least one chronic
medical condition (%)
18•Is RSV of public health importance among adults aged 50–59
years at increased risk of severe RSV disease? Public Health Problem: Work Group interpretation
NoProbably
NoProbably
YesYes VariesDon’t
know
EtR Domain: Benefits and Harms
Among adults aged 50 -59 years at increased risk of severe RSV disease:
•How substantial are the desirable anticipated effects of RSV vaccination?
•How substantial are the undesirable anticipated effects of RSV vaccination?
•Do the desirable effects outweigh the undesirable effects?
20GRADE Framework: PICO Question
Population Adults aged 50 –59 years at increased risk of severe RSV
disease
Intervention RSV Vaccine:
GSK Arexvy (1 dose IM) or Pfizer Abrysvo (1 dose IM) or
Moderna mResvia (1 dose IM)
Comparison No RSV vaccine
Outcomes ▪Medically attended RSV lower respiratory tract disease (LRTD)
▪Hospitalization for RSV respiratory illness
▪Death due to RSV respiratory illness
▪Serious Adverse Events (SAEs)
▪Inflammatory neurologic events (e.g., Guillain -Barré syndrome)
IM: intramuscular
21•Protein subunit vaccines : GSK’s Arexvy , Pfizer’s Abrysvo
•mRNA vaccine : Moderna’s mResvia  (not currently licensed for use in adults
aged <60 years)
•Policy question is not product -specific, so additional RSV vaccines eventually
licensed in adults aged 50 -59 years at increased risk of severe RSV disease
would be included in an existing recommendation
•All three vaccines are based on the same RSV antigen: F protein, stabilized in
prefusion conformation ( preF )
•Where relevant, we will show product -specific considerations outside of
GRADEFor GRADE, we are treating RSV vaccination with any
of the three licensed products as a single intervention
GRADE: Grading of Recommendations, Assessment, Development and Evaluation. https://www.cdc.gov/acip/grade/index.html
22GSK’s Arexvy  vaccine in adults aged 50 –59 years at increased risk of severe RSV disease,
Benefits: Geometric Mean Ratio (GMR) of neutralizing antibody titers1
a) Sero -response was defined as ≥4 -fold increase in the neutralization titer compared with pre -vaccination.
b) GMR at 30 days post -vaccination. The manufacturer calculated GMR as Cohort 2 / Cohort 1a. However, here, the reciprocal is shown : Cohort 1a / Cohort
2. GMR values >1 indicate higher geometric mean titers in Cohort 1a (adults 50 –59 at increased risk), compared with Cohort 2 (ad ults ≥60).
c) Noninferiority objective was lower bound of the GMR confidence interval ≥0.67, when evaluating the GMR Cohort 1a / Cohort 2, and the lower limit of
the CI around the sero -response rate difference ≥ -10%, when evaluating Cohort 1a minus Cohort 2.
d) Serological assays for the determination of antibodies against RSV -A and RSV -B are performed by neutralization assay. The corres ponding antibody titers
were expressed in ED60 (serum estimated dilution inducing 60% inhibition in plaque -forming units). Assessed at Day 31 , where Da y 1 was day of
vaccination.
1. Ferguson M, et al. Noninferior Immunogenicity and Consistent Safety of Respiratory Syncytial Virus Prefusion F Protein Vaccin e in Adults 50 -59 Years
Compared to ≥60 Years of Age. Clin Infect Dis. 2024 Oct 15;79(4):1074 -1084. https://pubmed.ncbi.nlm.nih.gov/39099093/  N n with sero -responsea,
30 days post -vaccinationN n with sero -responsea,
30 days post -vaccinationGMR (95% CI)b, 30
days post -vaccinationMet
Noninferiority
Objectivec
Cohort 1a: Adults aged 50 –59
years at increased risk of severe
RSV diseaseCohort 2: Adults aged ≥60 years Cohort 1a vs. Cohort 2
RSV-Ad343 298 (86.9%) 342 275 (80.4%) 1.20 (1.05, 1.37) Yes
RSV-Bd 343 280 (81.6%) 341 254 (74.5%) 1.25 (1.10, 1.41) Yes
Abbreviations: CI = confidence interval; GMR = geometric mean ratio
23Pfizer’s Abrysvo  vaccine in adults aged 50 –59 years at increased risk of severe RSV disease,
Benefits: Geometric Mean Ratio (GMR) of neutralizing antibody titers1
a) Sero -response was defined as achieving a ≥4 -fold rise from baseline (before vaccination), if the baseline measurement was above the lower limit of
quantification (LLOQ). If the baseline measurement was below the LLOQ, a postvaccination assay result ≥4 x LLOQ was considere d a sero -response.
b) GMRs (ratio of geometric mean titers in Group 1, compared to Group 2) and 2 -sided CIs were calculated by exponentiating the diff erence in least square
means and the corresponding CIs based on analysis of log -transformed titers using a regression model with population groups, bas eline log -transformed
titers and sex as covariates.
c) Noninferiority objective was not defined for the subset of participants aged 50 -59 years. For the full study population aged 18 -59 years, noninferiority
criteria were met: lower bound of the GMR confidence interval ≥0.67, and the lower limit of the CI around the sero -response rate difference ≥ -10%.
1. https://clinicaltrials.gov/study/NCT05842967 , https://pubmed.ncbi.nlm.nih.gov/37018468/ , https://www.cdc.gov/acip/downloads/slides -2024 -06-26-
28/02 -RSV-Adult -Munjal -508.pdf , unpublished data obtained from manufacturerN n with sero -responsea,
1 month post -vaccinationN n with sero -responsea,
1 month post -vaccinationGMR (95% CI)b, one
month post -vaccinationMet
Noninferiority
Objectivec
Group 1: Adults aged 50 –59 years
at increased risk of severe RSV
diseaseGroup 2: Adults aged ≥60 years Group 1 vs. Group 2
RSV-A 206 193 (93.7%) 534 450 (84.3%) 1.54 (1.33, 1.78) N/Ac
RSV-B 207 195 (94.2%) 534 457 (85.6%) 1.52 (1.30, 1.79) N/Ac
Abbreviations: CI = confidence interval; GMR = geometric mean ratio
24Moderna’s mResvia  vaccine in adults aged 50 –59 years at increased risk of severe RSV
disease, Benefits: Geometric Mean Ratio (GMR) of neutralizing antibody titers1
a) Seroresponse  at a participant level was defined as a change from below the lower limit of quantification (LLOQ) to equal or above 4 x LLOQ , or at least a
4-fold increase if baseline (pre -vaccine) was equal to or above the LLOQ.
b) GMRs (ratio of geometric mean titers in Group 1, compared to Group 2) and 2 -sided CIs were estimated using an Analysis of Covari ance model, with log -
transformed antibody levels at Day 29 post -baseline as the dependent variable, treatment group as the explanatory variable, and log-transformed
baseline antibody level as a covariate. The resulting least square means, difference of least square means, and 95% CIs (base d on t-distribution) were
back transformed to the original scale for the estimated geometric mean titer and GMR.
c) Noninferiority objective was not defined for the subset of participants aged 50 -59 years. For the full study population aged 18 -59 years, noninferiority
criteria were met: lower bound of the GMR confidence interval ≥0.67, and the lower limit of the CI around the sero -response rate difference ≥ -10%.
1. https://clinicaltrials.gov/study/NCT06067230 , https://pubmed.ncbi.nlm.nih.gov/38091530/ , unpublished data obtained from manufacturerN n with sero -responsea,
28 days post -vaccinationN n with sero -responsea,
28 days post -vaccinationGMR (95% CI)b, 28
days post -vaccinationMet
Noninferiority
Objectivec
Group 1: Adults aged 50 –59
years at increased risk of severe
RSV diseaseGroup 2: Adults aged ≥60 years Group 1 vs. Group 2
RSV-A 303 259 (85.5%) 1513 1119 (74.0%) 1.13 (1.01, 1.28) N/Ac
RSV-B 302 201 (66.6%) 1511 853 (56.5%) 1.10 (0.99, 1.23) N/Ac
Abbreviations: CI = confidence interval; GMR = geometric mean ratio
25Outcome Importance Data SourcesEffect Estimate,
Geometric mean titer ratioaPooled effect estimate,
efficacyb (95% CI)
in adults aged ≥60 yearsAdjustments to certainty
assessment
Medically attended RSV
LRTDImportantThree phase 3
RCTs in adults
aged <60
years1–3
Three phase 3
RCTs in adults
aged ≥60
years4–6Adults 50 –59 at increased risk vs.
adults ≥60:
RSV-A: 1.20 (95% CI: 1.05, 1.37)1
RSV-B: 1.25 (95% CI: 1.10, 1.41)1
RSV-A: 1.54 (95% CI: 1.33, 1.78)2
RSV-B: 1.52 (95% CI: 1.30, 1.79)2
RSV-A: 1.13 (95% CI: 1.01, 1.28)3
RSV-B: 1.10 (95% CI: 0.99, 1.23)369.3% (51.7, 80.6)
Assessed using 16 –23 months mean
follow up per participant4–6Indirectness (serious)c
Hospitalization for RSV
respiratory illnessCritical76.7% (8.3, 94.1)
Assessed using 9 –16 months mean
follow up per participant4–6Indirectness (serious)c
Imprecision (very serious)d
Strong associatione
Death due to RSV
respiratory illnessCritical Zero events observed Unable to evaluate
CI: confidence interval, LRTD: lower respiratory tract disease, RCT: randomized controlled trial
a) Titers assessed through neutralization assay one month after vaccination. Data from participants aged <50 years were excluded .
b) Pooled estimate using data from all interventional studies for each outcome generated using Mantel -Haenszel random effects model . Efficacy was calculated as 1 – incidence rate ratio. Events were included if they
occurred >14 days post -vaccination.
c) Serious concern for indirectness as the outcome was evaluated using immunobridging  data as a surrogate for vaccine efficacy and there is no established correlate of protection.
d) Very serious concern for imprecision due to the confidence interval in adults 60 and older containing estimates for which dif ferent policy decisions might be considered, and for fragility of the estimate. Fragility refers
to a situation in which estimates of the magnitude of effect and CIs may appear robust, but due to small numbers of events, r eallocation of <5 events from control to intervention group may render different results.
e) The relative rate for this outcome was <0.5 with consistent evidence from all 3 studies, with no significant concern for conf ounding. Therefore, this was considered to be a large effect size.
1. Ferguson M, et al. Noninferior Immunogenicity and Consistent Safety of Respiratory Syncytial Virus Prefusion F Protein Vaccin e in Adults 50 -59 Years Compared to ≥60 Years of Age. Clin Infect Dis. 2024 Oct
15;79(4):1074 -1084. https://pubmed.ncbi.nlm.nih.gov/39099093/
2. https://clinicaltrials.gov/study/NCT05842967 , https://www.cdc.gov/acip/downloads/slides -2024 -06-26-28/02 -RSV-Adult -Munjal -508.pdf , unpublished data obtained from manufacturer
3. https://clinicaltrials.gov/study/NCT06067230 , unpublished data obtained from manufacturer
4. Papi  A, et al. Respiratory Syncytial Virus Prefusion F Protein Vaccine in Older Adults. NEJM 2023; 388:595 –608. https://pubmed.ncbi.nlm.nih.gov/36791160/ , unpublished data obtained from manufacturer
5. Walsh EE, et al. Efficacy and Safety of a Bivalent RSV Prefusion F Vaccine in Older Adults. N Engl J Med. 2023 Apr 20;388(16) :1465-1477. https://pubmed.ncbi.nlm.nih.gov/37018468 , unpublished data obtained from
manufacturer
6. Wilson E, et al. Efficacy and Safety of an mRNA -Based RSV PreF  Vaccine in Older Adults. N Engl J Med. 2023 Dec 14;389(24):2233 -2244. https://pubmed.ncbi.nlm.nih.gov/38091530/ , unpublished data obtained from
manufacturerRSV vaccination in adults aged 50 –59 years at increased risk of severe RSV disease
Benefits: randomized studies , immunobridging
26Outcome Importance Data SourcesPooled effect estimate,
Vaccine Effectiveness (95%
CI)aAdjustments to certainty
assessment
Medically attended RSV
LRTDb ImportantThree case -control studies (test -
negative design) in adults ≥60
years1–3
One retrospective cohort study
(target trial emulation) in adults
≥60 years478% (74, 82)c Indirectness (serious)d
Strong associatione
Hospitalization for RSV
respiratory illnessCritical 80% (73, 85)c Indirectness (serious)d
Strong associatione
Death due to RSV
respiratory illnessCritical No data available Unable to evaluateRSV vaccination in adults aged 50 –59 years at increased risk of severe RSV disease
Benefits: observational studies
CI: confidence interval, LRTD: lower respiratory tract disease
a)Pooled estimate using data from observational studies for each outcome generated using Mantel -Haenszel random effects model with  weights assigned using standard error back
calculation.
b)Surrogate outcome was used to evaluate this outcome: RSV -associated ED visit, or either RSV -associated ED visit or hospitalizati on, depending availability by study.
c)Pooled effectiveness estimate reflects a mean or median of 2 –4 months after vaccination in each study.
d)Serious concern for indirectness because study participants were from the general population 60 and older, not 50 -59 with condit ions that increase risk.
e)The relative rate for this outcome was <0.5 with consistent evidence from all 4 studies, with no significant concern for conf ounding. Therefore, this was considered to be a large effect size.
1.Surie D, et al. RSV Vaccine Effectiveness Against Hospitalization Among US Adults 60 Years and Older. JAMA. 2024 Oct 1;332(13 ):1105-1107. https://pubmed.ncbi.nlm.nih.gov/39230920/
2.Payne AB, et al. Respiratory syncytial virus (RSV) vaccine effectiveness against RSV -associated hospitalisations  and emergency department encounters among adults aged 60 years and older
in the USA, October, 2023, to March, 2024: a test -negative design analysis. Lancet. 2024 Oct 19;404(10462):1547 -1559. https://pubmed.ncbi.nlm.nih.gov/39426837/
3.Pfizer -sponsored study: Tartof  SY , et al. Estimated Vaccine Effectiveness for Respiratory Syncytial Virus -Related Lower Respiratory Tract Disease. JAMA Netw  Open. 2024 Dec
2;7(12):e2450832. https://pubmed.ncbi.nlm.nih.gov/39671195/
4.Bajema KL, et al. Respiratory syncytial virus vaccine effectiveness among US veterans, September, 2023 to March 2024: a targe t trial emulation study. Lancet Infect Dis. 2025 Jan 20:S1473 -
3099(24)00796 -5. https://pubmed.ncbi.nlm.nih.gov/39848264/
27a)Within 6 months after study intervention.
b)Pooled estimate using data from all studies for this outcome generated using a Mantel -Haenszel fixed effect model. Data were lim ited
to participants aged 50 –59 years.
c)Serious concern for imprecision due to the confidence interval containing estimates for which different policy decisions migh t be
considered.
d)Serious concern for inconsistency because the point estimates between the studies differed substantially, although the confid ence
intervals overlapped.
e)Within 42 days after vaccination.
1.Ferguson M, et al. Noninferior Immunogenicity and Consistent Safety of Respiratory Syncytial Virus Prefusion F Protein Vaccin e in Adults
50-59 Years Compared to ≥60 Years of Age. Clin Infect Dis. 2024 Oct 15;79(4):1074 -1084. https://pubmed.ncbi.nlm.nih.gov/39099093/ ,
unpublished data obtained from manufacturer
2.https://clinicaltrials.gov/study/NCT05842967 , https://www.cdc.gov/acip/downloads/slides -2024 -06-26-28/02 -RSV-Adult -Munjal -
508.pdf , unpublished data obtained from manufacturerOutcome Importance Data SourcesPooled effect
estimate, relative risk
(95% CI)Concerns in certainty
assessment
Serious adverse events
(SAEs)aCritical Two phase 3 RCTs in
adults aged <60 years at
increased risk of severe
RSV disease1,21.13 (0.50, 2.59)bImprecision (serious)c
Inconsistency (serious)d
Inflammatory neurologic
eventseCritical Zero events observed Unable to evaluateRSV vaccination  in adults aged 50 –59 years at increased risk of severe RSV disease
Harms
28Summary of GRADE for RSV vaccination in adults aged 50 –59 years at
increased risk of severe RSV disease
Outcome ImportanceDesign
(# of studies)Findings
In adults aged 50 -59 years at increased risk of severe RSV
disease:Evidence
type
Benefits
Medically attended RSV
lower respiratory tract
disease (LRTD)ImportantRCT (3) RSV vaccination likely reduces medically attended RSV LRTD Moderate
Observational (3) RSV vaccination may reduce medically attended RSV LRTD Low
Hospitalization for RSV
respiratory illnessCriticalRCT (3) RSV vaccination may reduce hospitalization for RSV respiratory illness Low
Observational (4) RSV vaccination may reduce hospitalization for RSV respiratory illness Low
Death due to RSV
respiratory illnessCritical RCT (3) Zero events observedUnable to
evaluate
Harms
Serious adverse events Critical RCT (2)RSV vaccination may result in little to no difference in serious adverse
eventsLow
Inflammatory neurologic
eventsCritical RCT (2) Zero events observedUnable to
evaluate
RCT: randomized controlled trial
29•Population benefits of RSV vaccination compared with risk of Guillain -
Barre syndrome (GBS), for protein subunit vaccines
•Duration of vaccine protection and potential to restore protection through
revaccination
•Immunogenicity in immunocompromised personsAdditional information on benefits/harms for adults aged
50–59 years at increased risk of severe RSV disease
30▪On January 7th, the U.S. Food and Drug Administration ( FDA) required revision of the
Prescribing Information for GSK’s Arexvy2 and Pfizer’s Abrysvo3 Warnings and Precautions
section to include  the following:
▪The results of a postmarketing  observational study suggest an increased risk of Guillain -Barré syndrome
(GBS) during the 42 days following vaccination with [ Abrysvo /Arexvy ].
▪Available data suggest that risk is similar to, and potentially greater than, that of other
currently licensed and recommended adult vaccines.
▪The analyses of all GBS cases based on claims data suggest an increased risk of GBS during the 42 days
following vaccination, […] with an estimated 9 excess cases of GBS per million doses of Abrysvo , and an
estimated 7 excess cases of GBS per million doses of Arexvy  administered to individuals 65 years of age
and older.Available FDA data support existence of increased risk of
GBS after protein subunit RSV vaccination1 in adults ≥65yrs
1.GSK’s Arexvy  and Pfizer’s Abrysvo  are protein subunit RSV vaccines. Moderna’s mResvia  is an mRNA RSV vaccine, not a protein subunit vaccine. To date, Moderna’s
mResvia  vaccine has NOT been associated with increased risk of Guillain -Barré syndrome. Post -licensure safety surveillance for mResvia  began recently in June 2024.
2.https://www.fda.gov/media/167805/download
3.https://www.fda.gov/media/168889/download
31▪The Work Group emphasized that risk of Guillain -Barre syndrome (GBS) associated with
protein subunit RSV vaccines1 should be considered in the context of the public health
benefits of RSV vaccination.
▪In June and October 2024 , ACIP reviewed results of mathematical modeling analyses
comparing the numbers of RSV -associated hospitalizations, intensive care unit (ICU)
admissions, and deaths preventable per 1 million persons vaccinated vs. the numbers of
potential vaccine -attributable GBS cases.2
▪This analysis has been updated to account for the most up to date information on protein
subunit RSV vaccine effectiveness, duration of protection, and GBS risk1, and has been applied
to adults aged 50 –59 years at increased risk of severe RSV disease.
▪The background risk of GBS in a study population influences the excess GBS case estimates and may differ
between studies, precluding direct comparisons to excess GBS case estimates from other vaccine studies or
populations.Available FDA data support existence of increased risk of
GBS after protein subunit RSV vaccination1 in adults ≥65yrs
1.GSK’s Arexvy  and Pfizer’s Abrysvo  are protein subunit RSV vaccines. Moderna’s mResvia  is an mRNA RSV vaccine, NOT a protein subunit vaccine. To date, Moderna’s
mResvia  vaccine has NOT been associated with increased risk of Guillain -Barré syndrome. Post -licensure safety surveillance for mResvia  began recently in June 2024.
2.https://www.cdc.gov/acip/downloads/slides -2024 -10-23-24/06 -RSV-Adult -Melgar -508.pdf
321.Range of outcomes avertable was calculated using adjusted 95% confidence interval of RSV -associated incidence of the outcome obs erved in RSV -NET.
2.FDA self -controlled case series analysis, among CMS Medicare beneficiaries ≥65 years with Parts A, B, and D coverage who did not  have a GBS claim in the 365 days before vaccination. Analysis based on
diagnoses of GBS in inpatient claims data in risk interval (1 –42 days after RSV vaccination) compared to control interval (43 –90 days after RSV vaccination). GBS cases identified using ICD -10 diagnosis of GBS in
primary position of inpatient claims coding with chart verification requiring Brighton Collaboration Level 1 –3 certainty. Estima tes adjusted for outcome -dependent observation time, seasonality, and (when
chart review could not be performed) the positive predictive value of diagnostic codes in identifying chart -confirmed GBS cases.  Analysis includes patients with RSV vaccinations only through January 28, 2024
to allow for 90 -day post -vaccination observation and 90% or greater claims data completeness. Claims data through July 13, 2024.
3.Although CMS data were limited to Medicare beneficiaries aged ≥65 years, results are extrapolated here to apply to adults age d 50-59 years.
4.Credible range spans the lowest lower bound and highest upper bound of attributable risk estimates for the GSK and Pfizer RSV  vaccines.Estimated RSV -associated outcomes1 preventable  over 3 RSV Seasons  vs. attributable risk of Guillain -
Barre syndrome (GBS) estimated from self -controlled case series analysis through FDA -CMS partnership
data among adults aged ≥65 years, 42 -day risk interval2
Base case
Absolute risk from adults ≥65 years applied
directly to adults aged 50 -59 years:
0–184 attributable  cases of GBS per 1
million people vaccinated
Credit: Dr. David Hutton, U. MichiganPer 1 Million Doses of Protein Subunit  RSV Vaccines Administered to Adults
Aged 50 –59 Years3 at Increased Risk of Severe RSV Disease :
1304302,000
 -  1,000  2,000  3,000  4,000  5,000  6,000  7,000Hospitalizations
ICU Admissions
Deaths
(30–260)(150 –830)(700 –3,800)
33•In the clinical trials, protection provided by a single dose of RSV vaccine appears to wane over time.1,2,3
-Clinical trial data are available through 2 –3 RSV seasons, depending on manufacturer.
-Do not yet have real -world effectiveness data beyond the first RSV season.
•Clinical trial efficacy data evaluating revaccination are available only from GSK’s pivotal phase 3 trial (12 -month
revaccination interval).1
-Clinical efficacy in GSK’s pivotal phase 3 trial did not improve after revaccination at a 12 -month interval.What do we know so far about duration of protection and the need
for revaccination with adult RSV vaccines?
1. Ison MG, et al. Efficacy and Safety of Respiratory Syncytial Virus (RSV) Prefusion F Protein Vaccine (RSVPreF3 OA) in Older A dults Over 2 RSV Seasons. Clin Infect Dis. 2024 Jun 14;78(6):1732 -1744.
https://pubmed.ncbi.nlm.nih.gov/38253338/
2. Walsh EE, Eiras  D, Woodside J, et al. Efficacy, Immunogenicity, and Safety of the Bivalent RSV Prefusion F ( RSVpreF ) Vaccine in Older Adults Over 2 RSV Seasons, Clinical Infectious Diseases, 2025; ciaf061. Feb
2025. https://doi.org/10.1093/cid/ciaf061
3. Das R. Update on Moderna’s RSV vaccine, mRESVIA  (mRNA -1345), in adults ≥60 years of age [Presentation slides]. Presented at the Advisory Committee on Immunization Practices me eting, Atlanta, GA; June 26,
2024. https://www.cdc.gov/vaccines/acip/meetings/downloads/slides -2024 -06-26-28/04 -RSV-Adult -Das-508.pdf
34Clinical efficacy of 1 and 2 doses of GSK RSV vaccine ( Arexvy ) from
GSK’s phase 3 clinical trial
GSK RSV vaccine doses Vaccine efficacy (%) against RSV -
associated lower respiratory tract
disease
Single dose, season 1 only (median
follow -up 6.7 months during season 1)182.6 (96.95% CI: 57.9, 94.1)
Single dose, season 2 only (median
follow -up 6.3 months during season 2)256.1 (95% CI: 28.2, 74.4)
Two doses, season 2 only (median
follow -up 6.3 months during season 2)355.9 (95% CI: 27.9, 74.3)
CI=confidence interval
Ison MG, et al. Efficacy and Safety of Respiratory Syncytial Virus (RSV) Prefusion F Protein Vaccine (RSVPreF3 OA) in Older A dults Over 2 RSV Seasons. Clin Infect Dis. 2024 Jun 14;78(6):1732 -1744.
https://pubmed.ncbi.nlm.nih.gov/38253338/
1.Efficacy of 1 dose RSVPreF3 OA given pre -season 1 in preventing RSV -LRTD over season 1.
2.Efficacy of 1 dose RSV PreF3 OA given pre -season 1 in preventing RSV -LRTD over season 2.
3.Efficacy of 1 dose RSV PreF3 OA given pre -season 1 and a 2nd dose given pre -season 2 in preventing RSV -LRTD over season 2. Analysis includes data collected from participants who received R SVPreF3 OA as
dose 1 and dose 2 for the analysis of the revaccination regimen, and from participants who received placebo as dose 1 and 2 ( com parator group).Revaccination at 12
months did not improve
protection against
clinical disease
35•In the clinical trials, protection provided by a single dose of RSV vaccine appears to wane over time.1,2,3
-Clinical trial data are available through 2 –3 RSV seasons, depending on manufacturer.
-Do not yet have real -world effectiveness data beyond the first RSV season.
•Clinical trial efficacy data evaluating revaccination are available only from GSK’s pivotal phase 3 trial (12 -month
revaccination interval).1
-Clinical efficacy in GSK’s pivotal phase 3 trial did not improve after revaccination at a 12 -month interval.
•Immunogenicity data at various revaccination intervals are being studied
-GSK immunogenicity data at 12 -, 24-, and 36 -month revaccination intervals have shown a weaker humoral
immune response compared with the response after dose 1.4
-Pfizer immunogenicity data at a 12 -month revaccination interval has also shown a weaker humoral immune
response compared with the response after dose 1.5
-Moderna immunogenicity data at 12 - and 24 -month revaccination intervals have met prespecified non-
inferiority objectives compared with dose 1,3,6 but revaccination with a 24 -month interval showed lower peak
GMT compared with dose 1.What do we know so far about duration of protection and the need
for revaccination with adult RSV vaccines?
1. Ison MG, et al. Efficacy and Safety of Respiratory Syncytial Virus (RSV) Prefusion F Protein Vaccine (RSVPreF3 OA) in Older Adults  Over 2 RSV Seasons. Clin Infect Dis. 2024 Jun 14;78(6):1732 -1744. https://pubmed.ncbi.nlm.nih.gov/38253338/
2. Walsh EE, Eiras  D, Woodside J, et al. Efficacy, Immunogenicity, and Safety of the Bivalent RSV Prefusion F ( RSVpreF ) Vaccine in Older Adults Over 2 RSV Seasons, Clinical Infectious Diseases, 2025; ciaf061. Feb 2025. https://doi.org/10.1093/cid/ciaf061
3. Das R. Update on Moderna’s RSV vaccine, mRESVIA  (mRNA -1345), in adults ≥60 years of age [Presentation slides]. Presented at the Advisory Committee on Immunization Practices me eting, Atlanta, GA; June 26, 2024. https://www.cdc.gov/acip/downloads/slides -2024 -06-26-
28/04 -RSV-Adult -Das-508.pdf
4.Gerber, S. Arexvy  (Adjuvanted RSVPreF3). Presented at the Advisory Committee on Immunization Practices meeting, Atlanta, GA; April 16, 2025. https://www.cdc.gov/acip/downloads/slides -2025 -04-15-16/03 -Gerber -Adult -RSV-508.pdf
5. Walsh EE, et al. Respiratory Syncytial Virus Prefusion F Vaccination: Antibody Persistence and Revaccination. J Infect Dis. 2 024 Oct 16;230(4):e905 -e916. https://pubmed.ncbi.nlm.nih.gov/38606958/
6. Shaw CA et al. Safety and Immunogenicity of an mRNA -Based RSV Vaccine Including a 12 -Month Booster in a Phase 1 Clinical Trial in Healthy Older  Adults, The Journal of Infectious Diseases , Volume 230, Issue 3, 15 September 2024, Pages e647 –
e656,  https://pubmed.ncbi.nlm.nih.gov/38385566/
36Revaccination summary
•Efficacy data with revaccination at 12 months did not
show any improvement in clinical protection
•Revaccination DOES elicit a “boost” in neutralizing
antibody immune response
•For GSK, neutralizing antibody response does not
appear to reach post -dose 1 antibody levels, even after
waiting 3 years to revaccinate after the initial dose
•For Moderna, neutralizing antibody response to
revaccination at 12 and 24 -months met non-inferiority
criteria*  when compared with titers post -dose 1, but
were lower with the 24 -month interval
•Cellular immune response data available from
GSK shows that revaccination boosts T -cell response to
post -dose 1 level or higher •No clear trend yet visible in available data indicating
longer revaccination intervals yield more robust
antibody responses
-Would longer revaccination intervals result in a stronger
neutralizing antibody response? How long would that be
(5 years)?
•Are the “boosted” revaccination antibody responses
sufficient to provide clinical protection (even if lower
than the post -dose 1 response)?
•What is the relative importance of humoral versus
cellular immune responses in providing protection
against clinical disease?
•Do immunocompromised adults experience different
immune responses to revaccination?Knowns Unknowns
* Prespecified non -inferiority criteria were met when the lower bounds of the 95% confidence interval (CI) of the Geometric Mean  Titer Ratio (GMR) of RSV -
A and RSV -B neutralizing antibodies one month after dose #2 / one month after dose #1 were >0.667. 24 -month revaccination GMR of  RSV-A was 0.719 (95%
CI: 0.68, 0.76); 24 -month GMR of RSV -B was 0.705 (95% CI: 0.67, 0.74). Despite the statistically significant difference, prespecified non -inferiority criteria
were met because the lower bound of the 95% CI was >0.667.
37Summary of GSK Arexvy  immunogenicity studies
among adults with immune compromise
•Trial included adults aged ≥18 years with renal or lung transplant
•One month after a single dose of Arexvy , these participants had lower RSV neutralizing antibody
titers, compared with immunocompetent adults aged ≥50 years
•After a second dose of Arexvy  one month after the first, RSV neutralizing antibody titers increased
and were similar to those in immunocompetent adults aged ≥50 years at 2 months post -vaccination
•Measures of cellular immunity after Arexvy  vaccination were similar between immunocompromised
participants and immunocompetent participants
•No specific safety concerns identified. O ne participant experienced renal transplant rejection after
RSV vaccination*.
*Not interpreted as vaccine -related by the investigator
38Summary of Pfizer Abrysvo immunogenicity studies
among adults with immune compromise
•Trial included adults aged ≥18 years with autoimmune disorders on immunomodulator therapy, solid
organ transplant, end -stage renal disease on dialysis, or non -small cell lung cancer on therapy
•One month after a single dose of Abrysvo , these participants had similar RSV neutralizing antibody
titers, compared with immunocompetent adults aged ≥60 years from Pfizer’s main phase 3 trial
•The neutralizing antibody response in participants with autoimmune disorders on immunomodulator
therapy and solid organ transplant appeared lower than in adults with end -stage renal disease
•A second dose of Abrysvo  one month after the first did not appreciably increase neutralizing antibody
titers
•No specific safety concerns identified. O ne participant experienced renal transplant rejection* and
one participant experienced lung transplant rejection* after RSV vaccination.
*Not interpreted as vaccine -related by the investigator
39Benefits and Harms of RSV vaccine in  adults aged 50 –59 years at increased
risk of severe RSV disease
▪How substantial are the desirable anticipated effects among adults aged 50 –59 years at increased
risk of severe RSV disease
▪How substantial are the undesirable anticipated effects among adults aged 50 –59 years at
increased risk of severe RSV disease?
▪Do the desirable effects outweigh the undesirable effects among adults aged 50 –59 years at
increased risk of severe RSV disease?Minimal Small Moderate Large Varies Don’t know
Minimal Small Moderate Large Varies Don’t know
Favors intervention (RSV vaccine)
Favors comparison (no vaccine)
Favors both
Favors neither
UnclearMinority
opinion
Values and preferences
- Do adults aged 50 –59 years at increased risk of severe RSV disease  feel the
desirable effects of RSV vaccination are large relative to the undesirable effects?
- Is there important variability in how these adults value the main outcomes?
416.5
10.6
10.712.2
17.1
25.132.7
41.0
33.148.6
31.2
31.1
0 25 50 75 100Age ≥75 (N=326)Age 60 -74 (N=977)Age 18 -59 (N=2,799)
Weighted %Very concerned Moderately concerned A little concerned Not at all concernedConcern About Getting RSV Disease Among Adults Aged ≥18 Years, by
Age Group, Omnibus Surveys, April 4 –26, 2024 (N=4,102)
Omnibus Surveys: data for this analysis were collected through the Ipsos KnowledgePanel  and NORC AmeriSpeak  Omnibus Surveys, which use probability -based panels to survey a nationally representative
sample of U.S. adults aged 18 years and older. CDC fields questions about vaccination status, intent, knowledge, attitudes, b eliefs, and behaviors on each survey for 2 waves each month, for a combined
sample size of ~4,000 respondents. These slides present results from April 2024. Data were weighted to represent the non -institu tionalized U.S. population and mitigate possible non -response bias. All
responses are self -reported.
42Behavioral & Social Drivers of RSV Vaccination Among Adults Aged 60 –74
Years at Increased Risk** for Severe RSV Disease, November 2024
National Immunization Survey -Adult COVID Module (NIS -ACM)
**A respondent was considered to be at increased risk for severe RSV disease if they had any of the following: chronic lung d iseases, diabetes with insulin use, heart conditions, immunocompromised state, solid organ or blood stem
cell transplant (including bone marrow transplant), cancer, liver disease, sickle cell disease or thalassemia, or currently l ives in a nursing home.
NIS-ACM methods: Data from adults age ≥18 years are collected by telephone interview using a random -digit -dialed sample of cell telephone numbers  stratified by state, the District of Columbia, five local jurisdictions (Bexar County
TX, Chicago IL, Houston TX, New York City NY, and Philadelphia County PA), and Puerto Rico and the U.S. Virgin Islands. Data are weighted to represent the non -institutionalized U.S. population and mitigate possible bias that can
result from an incomplete sample frame (exclusion of households with no phone service or only landline telephones) or non -respon se. All responses are self -reported. For more information about the survey, see
https://www.cdc.gov/nis/about/index.html  and https://www.cdc.gov/nis/media/pdfs/2025/02/NISACMQuestionnaireQ12025_508 -2_2025.pdf.496479
32
020406080100
Concerned about
RSV diseaseConfidence in RSV
vaccine safetyConfidence that
RSV vaccine is
important
protectionHealth care
provider
recommended
RSV vaccineWeighted % of Respondents Selecting
Response Option(s) to Questions About
RSV and RSV Vaccine Responses to questions:
“Very or moderately concerned about
getting RSV”
“Thinks the RSV vaccine is completely
or very safe”
“Thinks the RSV vaccine is very or
somewhat important to protect
yourself against RSV”
“Doctor, nurse, or other health
professional recommended that you
get an RSV vaccine since Fall 2023”
432122222426272727273030303030333334343535353537373717201715131019171414161119221014161412141591213124442
374447
373935374039
40272742372430373234
303531311816
241814
2616212217151925211617
2522162016
27161820
0255075100
Aug25-31
Sep1-7
Sep8-14
Sep15-21
Sep22-28
Sep29-Oct5
Oct6-12
Oct13-19
Oct20-26
Oct27-Nov2
Nov3-9
Nov10-16
Nov17-23
Nov24-30
Dec1-7
Dec8-14
Dec15-21
Dec22-28
Dec29-Jan4
Jan5-11
Jan12-18
Jan19-25
Jan26-Feb1
Feb2-8
Feb9-15Weighted %
3031313131323535363740414142434444444446464646464647121013131513141699776787798115115511123939403733363732
33373432292833
2525283226
2926
29272322192017202119141721171920252417
2424191618201720222020
0255075100
Aug18-24
Aug25-31
Sep1-7
Sep8-14
Sep15-21
Sep22-28
Sep29-Oct5
Oct6-12
Oct13-19
Oct20-26
Oct27-Nov2
Nov3-9
Nov10-16
Nov17-23
Nov24-30
Dec1-7
Dec8-14
Dec15-21
Dec22-28
Dec29-Jan4
Jan5-11
Jan12-18
Jan19-25
Jan26-Feb1
Feb2-8
Feb9-15Weighted %RSV Vaccination Status and Intent Among Adults Aged ≥75 Years and 60 –
74 Years at Increased Risk**  for Severe RSV, through February 15, 2025
National Immunization Survey -Adult COVID Module (NIS -ACM)
Probably or definitely will not get RSV vaccine
Probably will get RSV vaccine or unsure
Definitely will get RSV vaccine
Received RSV vaccineWeekly RSV Vaccination Status and Intent, NIS -ACM
**A respondent was considered to be at increased risk for severe RSV disease if they had any of the following: chronic lung d iseases, diabetes with insulin use, heart conditions, immunocompromised state, solid organ or blood
stem cell transplant (including bone marrow transplant), cancer, liver disease, sickle cell disease or thalassemia, or curren tly lives in a nursing home.
NIS-ACM methods: Data from adults age ≥18 years are collected by telephone interview using a random -digit -dialed sample of cell telephone numbers  stratified by state, the District of Columbia, five local jurisdictions (Bexar
County TX, Chicago IL, Houston TX, New York City NY, and Philadelphia County PA), and Puerto Rico and the U.S. Virgin Islands . Data are weighted to represent the non -institutionalized U.S. population and mitigate possible bias
that can result from an incomplete sample frame (exclusion of households with no phone service or only landline telephones) o r non-response. All responses are self -reported. For more information about the survey, see
https://www.cdc.gov/nis/about/index.html.Aged ≥75 years
•47% (95% CI: 45.0 -48.3) received
an RSV vaccine
•12% (95% CI: 6.1 -17.5) definitely
will get vaccinated
Aged 60 –74 years at increased risk
•37% (95% CI: 34.1 -40.6) received
an RSV vaccine
•12% (95% CI: 5.8 -18.5) definitely
will get vaccinatedAdults Aged 60 –74 Years at Increased Risk (n=18,880) Adults Aged ≥75 Years (n=95,706)
Risk of Guillain -Barre Syndrome (GBS)
1. Scherer LD, Shaffer VA, Patel N, Zikmund -Fisher BJ. Can the vaccine adverse event reporting system be used to increase vaccine a cceptance and trust? Vaccine. 2016 May 5;34(21):2424 -2429. https://pubmed.ncbi.nlm.nih.gov/27049120/
2. Prosser LA, Payne K, Rusinak  D, et al. Valuing health across the lifespan: health state preferences for seasonal influenza illnesses in patients of differ ent ages. Value Health. 2011;14(1):135 -143. https://pubmed.ncbi.nlm.nih.gov/21211495/  There are no data assessing how adults value protection against RSV
relative to potential risk of GBS.
A few considerations:
•Adults are willing to accept some rate of vaccine -associated adverse
events for the benefit of preventing disease1
•Individual baseline and vaccine -associated risk of GBS may differ by
age group and presence of chronic conditions
•Willingness to accept risk of GBS after vaccination may differ by age
and health status and perceived risk of RSV -associated disease2
44
45•About 20% of adults aged 18 –59 years say they are very or moderately
concerned about RSV, compared with approximately 30 –35% of adults
aged ≥60 years.
•Uptake of RSV vaccine through February 2025 was 37 –47% among
adults aged ≥60 years.
•We do not have data on how adults value protection against RSV versus
potential risk of GBS, but this may vary by age or other factors. Values: summary of the available evidence
Adults aged 50 –59 years at increased risk of severe RSV disease
Values
No Probably no Probably Yes Yes Varies Don’t know
Important uncertainty or variability
Probably important uncertainty or variability
Probably not important uncertainty or variability
No important uncertainty or variability
No known undesirable outcomes•Do adults aged 50 –59 years at increased risk of severe RSV disease feel that
the desirable effects of RSV vaccination are large relative to the undesirable
effects?
•Is there important uncertainty about, or variability in, how much  adults aged 50 –
59 years at increased risk of severe RSV disease value the main outcomes?
46Minority
opinion
Is it feasible to implement RSV vaccination for adults aged 50 –59 years at increased risk of
severe RSV disease ?Acceptability
Would recommending RSV vaccination for adults aged 50 –59 years at increased
risk of severe RSV disease  be acceptable to key stakeholders?
Feasibility
48Top RSV vaccination concerns and issues among adults age d60–74 years
with high -risk condition s*, Omnibus Surveys , December 12 –30, 2024
Omnibus Surveys: Data for this analysis were collected through the Ipsos KnowledgePanel  and NORC AmeriSpeak  Omnibus Surveys, which use probability -based panels to survey a nationally representative sample of U.S.
adults aged 18 years and older. CDC fields questions about vaccination status, intent, knowledge, attitudes, beliefs, and beh aviors on each survey for 2 waves each month, for a combined sample size of ~4,000 respondents.
This slide presents results from December 2024. Data were weighted to represent the non -institutionalized U.S. population and mi tigate possible non -response bias. All responses are self -reported.*Includes self -reported chronic lung disease, heart conditions, solid organ or blood stem cell transplant, cancer (excluding bas al cell carcinoma and squamous cell carcinoma), diabetes, liver
disease, sickle cell disease or thalassemia, BMI (body mass index) ≥40, and immunocompromised state.
Other response options included: "Have not had time," "Vaccine fatigue," "Not eligible/ unsure if eligible," "Too close to an other vaccine," "Have enough immunity," "Concerned about
effectiveness," "Other," "Cost," "Got sick from past vaccine," "Could not find vaccine," "Allergic/other medical reason."

7.2%22.0%
13.2%37.5%
20.1%
0%10%20%30%40%50%60%70%80%90%100%% of respondents selecting response option (n=926)
Never Sometimes Half the time Most of the time Always
Unpublished data —CDC/University of Iowa/RAND survey conducted 6/3 -6/24/24. Question respondents (N=926) included Family Medicine  providers (N=300), General Internists
(N=306),  Pharmacists (N=295), and Pediatricians (N=25).58% of respondents report checking RSV vaccination eligibility for their adult
(aged  ≥60 years) patients prior to an appointment most or all the time
49
36.4%
28.0%
24.9%
22.5%
22.1%
20.8%
13.2%
12.1%
9.1%
8.4%
6.0%
5.5%
4.3%
4.0%
3.5%
2.0%
1.4%0% 20% 40% 60% 80% 100%
The patient will refuse vaccination
The patient has concerns about their out-of-pocket vaccination cost
Patients are tired of hearing about vaccines in general
They have a medical reason for not getting vaccinated
There isn’t enough time during a visit to discuss RSV vaccines
Other recommended vaccines for this age group are a bigger priority for me
There isn’t enough time during a visit to vaccinate
Other
Recommending COVID-19 vaccination could increase general vaccine…
Patients are tired of hearing about RSV vaccines
Relatively high level of resistance to RSV vaccines in my community
Patients in this age group are unlikely to experience severe RSV symptoms
Vaccination provides insufficient protection against RSV for this age group
Patients in this age group are unlikely to get RSV
Vaccination doesn’t reduce RSV severity for this age group
The RSV vaccine is unsafe for patients in this age group
Prior RSV makes vaccination is unnecessary for this age group% of respondents selecting response option (n=836)Anticipated vaccine refusal, patient financial concerns, and perceived patient
vaccine fatigue were the top reasons for not recommending RSV vaccination
50 Unpublished data —CDC/University of Iowa/RAND survey conducted 6/3 -6/24/24. Respondents for this question included Family Medicin e providers, General Internists,
Pharmacists, and Pediatricians. Respondents could select multiple answer choices. N=836.
Potential barriers to implementation of a risk -based
recommendation for RSV vaccine among adults aged 50 –59 years
•Vaccine acquisition cost is relatively high
-Costly upfront investment to carry RSV vaccines
•Most RSV vaccines are administered in pharmacies
-Risk assessment and billing for risk -based recommendations may be challenging
•Increased vaccine schedule complexity for adults
-Limited time to discuss vaccines at appointments
-Increasing number of adult vaccines
-Multiple adult RSV vaccine products with different temperature requirements
for storage and handling
51
52•Approximately 50% of adults aged 60 –74 years with risk conditions have
no concerns about RSV vaccine
- Among those with concerns, top responses indicated lack of knowledge about RSV
vaccine, concern about serious side effects and lack of provider recommendation
•Providers check RSV vaccine eligibility about 60% of the time
-Top barriers for making a recommendation are related to concern about
patient vaccine fatigue and vaccine refusal
•Other implementation barriers include cost, challenges of a risk -based
recommendation in pharmacy settings, and schedule complexity Acceptability and Feasibility: Summary of the available evidence
Adults aged 50 –59 years at increased risk of severe RSV disease
Acceptability
•Would recommending RSV vaccines for adults aged 50 -59 years at
increased risk of severe RSV disease be acceptable to key
stakeholders?
No Probably No Probably Yes Yes Varies Don’t know
53
Feasibility
•Is it feasible to implement RSV vaccination among adults aged 50 -59
years at increased risk of severe RSV disease?
No Probably No Probably Yes Yes Varies Don’t know
54Minority
opinion
Resource Use
Is an RSV vaccine program for adults aged 50 –59 years at increased risk
of severe RSV disease a reasonable and efficient allocation of resources
Work Group considerations regarding societal resource use
toward RSV vaccination in older adults at current list prices
•RSV vaccination for adults aged 50 –59 years with risk factors for severe RSV disease
has an incremental cost -effectiveness ratio (ICER) of $43,070 (3 -year time horizon for
protein subunit vaccines) to $152,293 (2 -year time horizon for mRNA vaccine)
•Vaccination is likely cost -saving for certain risk conditions
•Substantial uncertainty in key parameters that impact cost effectiveness:
-Uncertainty in incidence of medically attended RSV illness, particularly hospitalizations
-Uncertainty in RSV -attributable mortality
-Uncertainty in duration of protection from a single dose of RSV vaccination
-Real -world vaccine effectiveness of Moderna mResvia ; analyses currently rely on clinical trial efficacy
estimates
•If RSV vaccine list prices were substantially reduced, then RSV vaccination may be a cost -
effective intervention for a broader adult population
56
Resource use
•Is RSV vaccination a reasonable and efficient allocation of resources in
adults aged 50 -59 years at increased risk of severe RSV disease?
No Probably No Probably Yes Yes Varies Don’t know
57
Equity
What would be the impact on health equity of recommending RSV
vaccination for:
Adults aged 50 –59 years at increased risk of severe RSV disease?
58
Median age of non -pregnant adults* aged ≥18 years with RSV -
associated hospitalizations by race and ethnicity** — RSV-NET,
2014 –2015 to 2022 –2023
UnweightedWeighted
%Median
AgeInterquartile
range (IQR)
Overall 17,847 - 69 (58–81)
White 10,755 62.2 73 (63–82)
Black 3,529 20.4 62 (50–71)
Hispanic 1,434 8.3 62 (48–76)
Asian or Pacific Islander 1,020 5.9 73 (59–83)
American Indian or Alaska
Native90 0.5 64 (54–73)
Multiple races 89 0.5 75 (58–84)
Unknown 367 2.1 68 (57–78)Median age of
hospitalization is
lower among Black,
Hispanic, and
American
Indian/Alaska Native
persons than White
and Asian/Pacific
Islander persons.
*Includes men and non -pregnant women.
**Black, White, American Indian/Alaska Native and Asian/Pacific Islander people were categorized as non -Hispanic; Hispanic peopl e could be of any race.
59
600100200300400500
Age 18-49 years Age 50 –59 years Age 60 –74 years Age ≥75 yearsRSV-associated hospitalizations per 100,000
populationBlack
Hispanic
White
Asian & Pacific IslanderRSV-associated hospitalization rates by age group and by race
and ethnicity, RSV -NET, 2018 –2019
Unpublished data from RSV -NET. Rates are adjusted using multipliers for the frequency of RSV testing during each season and the sensitivity of RSV diagnostic tests. Error bars represent
95% confidence intervals. Estimated rates exclude recorded hospitalizations among pregnant women. Black, White, and Asian/Pac ific Islander people were categorized as non -Hispanic;
Hispanic people could be of any race. Hospitalization rates among American Indian and Alaska Native persons are not shown due  to small numbers. There may be unmeasured
confounding, especially in the oldest age group. Although incidence appears lower in Black adults aged ≥75 years than in White adults, if Black adults are less likely to survive to age 80 or
90 years, then differences in underlying age distribution may be driving this finding. Black adults had a
hospitalization rate 2.3x
higher than White
adultsBlack adults had a
hospitalization rate 1.5x
higher than White adults
Black adults had a
hospitalization rate 1.9x
higher than White adults
60
61SOURCE: National Center for Health Statistics (NCHS), National Health and Nutrition Examination Survey (NHANES), 2015 –2018. All estimates are crude estimates with no age adjustment and age is age at interview. Error bars represent Korn and Graubard  95% confidence intervals. NHANES is representative of the
civilian, non -institutionalized U.S. population. For “narrow” definition: Severe obesity was defined as BMI ≥40 kg/m2. Diabetes with complication was defined as 1) having diabetes: self -reported diabetes, fasting plasma glucose ≥126 mg/dL, or he moglobin A1c ≥6.5%, AND 2) having one of the following complications of
diabetes assessed within the survey: serious heart disease as defined below, chronic kidney disease (stage 3, 4, or 5) define d as estimated glomerular filtration rate (eGFR) ˂60 (stages 3 –5) further defined below, or having self -reported diabetes and havin g a doctor previously told them that diabetes affected their eyes or
that they have retinopathy. Other complications of diabetes are not included in this definition. Serious heart disease was de fined based on self -report as diagnosed congestive heart failure, coronary heart disease, angina, or heart attack, or angina grades  1 or 2 determined by the Rose Angina Questionnaire. Asthma was
defined as self -reporting ever being diagnosed with asthma and still having asthma. Chronic kidney disease was defined as estima ted glomerular filtration rate (eGFR) ˂30 (stages 4 –5), and using a forward equation for adjustment of creatinine because of met hods changes. eGFR calculated using the 2021 CKD -EPI
creatinine equation (https://www.nejm.org/doi/10.1056/NEJMoa2102953). Urine albumin is not included in this definition. Chron ic obstructive pulmonary disease (COPD) was defined as self -reported diagnosed COPD, emphysema, or current chronic bronchitis. Live r condition was defined as self -reporting ever being
diagnosed with any kind of liver condition and still having any kind of liver condition. Having at least one of the above con ditions for the narrow definition was defined based on the seven (7) conditions listed. Among the fasting sample, ~94% had compl ete data for all reported medical conditions, ~6% were missing data
for one (1) medical condition, <1% were missing data for two (2) medical conditions, and none were missing data for three (3)  or more medical conditions. Estimates of having ≥1 condition are weighted using fasting sample weights. Prevalence of U.S. adults with ≥1 chronic medical condition using narrow definition of chronic
medical conditions* , by age and race
National Health and Nutrition Examination Survey (NHANES), 2015 —2018
40.744.4
30.439.0
27.040.1
15.231.8
0102030405060708090100
Aged 50-59 Years Aged ≥ 60 Years Prevalence of at least one chronic medical condition (%)
Non-Hispanic Black Non-Hispanic White Hispanic Non-Hispanic Asian*Narrow definition , at least one of:
• Serious heart disease
• Diabetes with complication
• Chronic obstructive pulmonary disease
• Asthma
• Severe obesity (BMI ≥40 kg/m2)
• Liver condition
• Chronic kidney disease, stage 4 or 5
BMI: body mass index
62RSV Vaccination Coverage Among Adults Aged 60 –74 Years at Increased Risk** for Severe RSV, by
December 28, 2024
National Immunization Survey -Adult COVID Module (NIS -ACM)
NA: estimate not reported because denominator is <30; AI/AN: American Indian or Alaska Native; NH/OPI: Native Hawaiian or Oth er Pacific Islander; CI: 95% confidence interval; Ref: Referent category.
*Statistically significant at p<0.05 compared to the referent category.
**A respondent was considered to be at increased risk for severe RSV disease if they had any of the following: self -reported chr onic lung diseases, diabetes with insulin use, heart conditions, immunocompromised state, solid organ or blood stem cell
transplant (including bone marrow transplant), cancer, liver disease, sickle cell disease or thalassemia, or currently lives in a nursing home.
NIS-ACM methods: Data from adults age ≥18 years are collected by telephone interview using a random -digit -dialed sample of cell telephone numbers  stratified by state, the District of Columbia, five local jurisdictions (Bexar County TX, Chicago IL, Houston TX,
New York City NY, and Philadelphia County PA), and Puerto Rico and the U.S. Virgin Islands. Data are weighted to represent th e non-institutionalized U.S. population and mitigate possible bias that can result from an incomplete sample frame (exclusion of
households with no phone service or only landline telephones) or non -response. All responses are self -reported. For more informa tion about the survey, see https://www.cdc.gov/nis/about/index.html.33.625.8*35.930.433.527.1*43.732.733.529.134.9*31.4
0 20 40 60 80 100OverallMultiple/Other, non-HispanicWhite, non-Hispanic (Ref)NH/OPI, non-HispanicHispanicBlack, non-HispanicAsian, non-HispanicAI/AN, non-HispanicMaleFemale (Ref)Rural (Ref)SuburbanUrban
Weighted % (95% CI)NAAge 60 –74 Years, at Increased Risk (n=13,919)
63Equity: Summary of the available evidence
Adults 50 –59 years at increased risk of severe RSV disease
•Overall rates of RSV among all race and ethnicity groups remain lower in adults
aged <60 years than adults 60 –74 and 75 years and older; however, Black
adults aged 50 –59 years had higher RSV hospitalization rates than White adults
•Chronic conditions that increase risk of severe RSV disease occur more
frequently among certain racial and ethnic groups aged 50 –59
•RSV vaccine uptake varies by race and ethnicity
64Equity
▪What would be the impact on health equity of recommending RSV vaccination
in adults aged 50 -59 years at increased risk of severe RSV disease?
Reduced
Probably reduced
Probably no impact
Probably increased
Increased
Varies
Don’t know
Summary
65
66DomainAmong adults aged 50–59 years at increased
risk of severe RSV diseaseWork Group Majority
Opinion
Public Health
ProblemIs RSV of public health importance? Yes/Probably yes
Benefits and
HarmsHow substantial are the desirable anticipated effects? Moderate
How substantial are the undesirable anticipated effects? Small
Do the desirable effects outweigh the undesirable effects? Favors intervention
ValuesDoes the target population feel the desirable effects are large
relative to the undesirable effects?Probably yes
Is there important variability in how patients value the outcomes?Probably important uncertainty or
variability
Acceptability Is the intervention acceptable to key stakeholders? Yes/Probably yes
Feasibility Is the intervention feasible to implement? Yes/Probably yes
Resource Use Is the intervention a reasonable and efficient allocation of resources? Yes/Probably yes
Equity What would be the impact on health equity? Probably increased
671.ACIP recommends that adults 50 –59 years of age who are at increased
risk of severe RSV diseasea receive a single dose of RSV vaccine.b,cProposed ACIP vote language
a.CDC will publish Clinical Considerations that describe chronic medical conditions and other risk factors for severe
RSV disease for use in this risk -based recommendation.
b.RSV vaccination is recommended as a single dose only. Persons who have already received RSV vaccination are NOT
recommended to receive another dose.
c.RSV vaccine can be administered with any product licensed in this age group.
68Evidence to Recommendations Framework
Summary: Work Group Interpretations
Balance of
consequencesUndesirable
consequences
clearly outweigh
desirable
consequences in
most settingsUndesirable
consequences
probably
outweigh
desirable
consequences in
most settingsThe balance
between
desirable and
undesirable
consequences is
closely balanced
or uncertainDesirable
consequences
probably
outweigh
undesirable
consequences in
most settingsDesirable
consequences
clearly outweigh
undesirable
consequences in
most settingsThere is
insufficient
evidence to
determine the
balance of
consequencesAmong adults aged 50 -59 years at increased risk of severe RSV disease:
Minority
opinion
69Evidence to Recommendations Framework
Summary: Work Group Interpretations
Is there sufficient information to move forward with a recommendation?
Yes NoAmong adults aged 50 -59 years at increased risk of severe RSV disease:
Minority
opinion
70Evidence to Recommendations Framework
Summary: Work Group Interpretations
We do not recommend the intervention
We recommend the intervention for individuals based on shared clinical decision -making
We recommend the interventionType of recommendation, adults aged 50 -59 years at increased risk of
severe RSV disease:
71•The Work Group also discussed which risk conditions should be included in a risk -based
recommendation for adults aged 50 -59 years.
-Should risk conditions be the same as those for adults aged 60 -74 years? Or should they be different?
•Discussion points favoring the same risk conditions as those outlined for adults aged 60 -74 years:
-Significant concerns about complexity for providers and patients in having a different list of risk conditions for adults
aged 50 -59 years than adults aged 60 -74 years.
-Adults aged 50 -59 years have similar conditions that increase risk of severe RSV disease as adults aged 60 -74 years.
•Discussion points favoring a narrower list of risk conditions than those outlined for adults aged 60 -
74 years:
-Due to increasing vaccine fatigue and complexity of the adult immunization schedule, perhaps focus for providers
and patients should be on a adults with a narrower list of risk conditions, who are at highest risk of severe RSV
disease
-While the vaccine looks to be cost -saving for certain risk conditions, recommending RSV vaccine for the same list of
risk conditions among adults aged 50 -59 as 60 -74 years is less cost -effective in adults aged 50 -59 than in those 60 -
74.
-There remains important uncertainty in whether revaccination can restore protection to levels seen after the first
dose. This may be a more important consideration when developing a recommendation for younger adults with
longer remaining life expectancy. Work Group considerations
72•Overall, the Work Group majority feels that risk conditions for a recommendation in
adults aged 50 -59 years should include the same conditions already outlined in the risk -
based recommendation for adults aged 60 -74 years
•With this recommendation, the Work Group stresses that additional data will be critical to
understand the optimal revaccination interval and that studies supporting the preferred
policy around revaccination are needed
•The Work Group also stresses the importance of ongoing safety surveillance monitoringWork Group considerations
For more information, contact CDC
1-800-CDC-INFO (232 -4636)
TTY:  1 -888-232-6348    www.cdc.gov
The findings and conclusions in this report are those of the authors and do not necessarily represent the official position
of the Centers for Disease Control and Prevention.
Acknowledgements
73• Adult RSV Vaccine Work Group
• CDC Coronavirus and Other Respiratory Viruses Division
• CDC Immunization Services Division
• CDC Immunization Safety Office
• National Center for Chronic Disease Prevention and Health Promotion
• National Center for Health Statistics
• FDA Center for Biologics Evaluation and Research
• David Hutton, University of Michigan

Summary: Evidence to Recommendations Framework (EtR): RSV Vaccination in Adults Aged 50 –59 years Amadea Britton, MD, Co -Lead Adult RSV Vaccine Work Group Michael Melgar, MD, Co -Lead Adult RSV Vaccine Work Group Diya Surie, MD, Co -Lead Adult RSV Vaccine Work Group Coronavirus and Other Respiratory Viruses Division (CORVD) Advisory Committee on Immunization Practices (ACIP) April 16, 2025National Center for Immunization and Respiratory Diseases 2•Should adults aged 50 –59 years at increased risk of…


07 Surie adult RSV 508

ACIP Adult RSV Work Group Clinical Considerations
RSV vaccination in Adults 50 –59 at increased risk of severe
RSV diseaseDiya Surie, MD
Michael Melgar, MD
Amadea Britton, MD
Co-Leads, Adult RSV Vaccine Work Group
Coronavirus and Other Respiratory Viruses Division (CORVD)
Advisory Committee on Immunization Practices (ACIP)
April 16, 2025National Center for Immunization and Respiratory Diseases
•Licensed products for use in adults aged 50 –59 years at increased risk of
severe RSV disease
•Adults aged 50 –59 years at increased risk of severe RSV disease
•Timing of RSV vaccination for the 2025 –2026 RSV season
•Coadministration of RSV vaccines with other vaccinesOverview
*Pfizer’s Abrysvo is also licensed and recommended for use in pregnancy to prevent RSV LRTD in
infants after birth. No other RSV vaccine should be administered in pregnancy .RSV vaccine FDA licensure for RSV prevention in adults,
as of April 16, 2025
20 30 40 50 60 70 80 90GSK's ArexvyPfizer's Abrysvo*Moderna's mResvia
Age (years)18
Licensure limited to adults at increased risk of
RSV lower respiratory tract disease (LRTD)Licensure is for the general
population of adults aged ≥60 years
*Pfizer’s Abrysvo  is also licensed and recommended for use in pregnancy to prevent RSV LRTD in
infants after birth. No other RSV vaccine should be administered in pregnancy .RSV vaccine FDA licensure  for RSV prevention in adults,
as of April 16, 2025
20 30 40 50 60 70 80 90GSK's ArexvyPfizer's Abrysvo*Moderna's mResvia
Age (years)18
Licensure limited to adults at increased risk of
RSV lower respiratory tract disease (LRTD)Licensure is for the general
population of adults aged ≥60 yearsIf mResvia  gains FDA licensure in high -risk adults 50 –59, it
would be included in an existing recommendation by default
Adults aged 50 –59 years at increased risk of
severe RSV disease
Proposed list of risk factors for the 50 –59 recommendation is
the same as that currently used for the 60 –74 recommendation
Neurological or neuromuscular conditions
causing impaired airway clearance or
respiratory muscle weaknessChronic cardiovascular
disease
Moderate or severe
immunocompromise Diabetes mellitus
complicated by chronic kidney disease,
neuropathy, retinopathy or other end -
organ damage or requiring treatment
with insulin or sodium -glucose
cotransporter -2 (SGLT2) inhibitorSevere obesity
(body mass index
≥40 kg/m2)Chronic lung
or respiratory
disease
End stage renal
disease/dialysis
dependenceChronic liver
diseaseChronic hematologic
conditions
Residence in a
nursing homeOther chronic medical conditions or risk factors that a
provider determines would increase risk of severe disease
due to viral respiratory infection (e.g., frailty)
Britton A, Roper LE, Kotton CN, et al. Use of Respiratory Syncytial Virus Vaccines in Adults Aged ≥60 Years: Updated Recommen dations of the Advisory Committee on Immunization Practices — United States,
2024. MMWR Morb  Mortal Wkly  Rep 2024;73:696 -702. DOI: http://dx.doi.org/10.15585/mmwr.mm7332e1 .
Includes information on risk of
Guillain -Barré syndrome for the
two subunit vaccines  (GSK’s
Arexvy , Pfizer’s Abrysvo )
Current RSV vaccine flyer
for healthcare providers
will be updated with any
new recommendation
https://www.cdc.gov/rsv/media/pdfs/2025/01/355818 -A_RSV_VaccineForOlderAdultsFlyer -01072025 -V9-WEB.pdf
Guidance on the timing of RSV vaccination is
unchanged
▪RSV vaccination should be given ONLY
to adults who have not yet received a
dose of RSV vaccine.
▪It is anticipated that adults may need
additional doses of RSV vaccine in the
future, but ideal revaccination timing
is not yet known. Adults who have already received
a dose of RSV vaccine should NOT
receive another dose at this time. RSV vaccination will have the
most benefit if given in late
summer or early fall .
▪This means from August to
October in most of the United
States.
▪Note this is not a formal seasonal
recommendation for RSV
vaccination. Eligible adults may
continue to receive RSV
vaccination year -round.
Co-administration of RSV vaccines with other
adult vaccines
11•With two exceptions,1,2 pre-specified non -inferiority criteria were met for
simultaneous vaccination, compared with separate administration.
•The Work Group notes our limited understanding of clinical significance of
decreased antibody titers with RSV vaccine co -administration. ACIP previously reviewed results from studies on co -
administration of RSV vaccine with influenza and mRNA
COVID -19 vaccines
1.Simultaneous administ ration of GSK’s Arexvy  with adjuvanted influenza vaccine resulted in lower H3N2 hemagglutination inhibition (HAI)
titers, compared with sequential administration. Humoral immune response against influenza A/Darwin H3N2 was also assessed po st-hoc via
microneutralization, which resulted in a geometric mean titer (GMT) ratio similar to the HAI GMT ratio, with a slightly narro wer confidence
interval. Non -inferiority criteria were not specified for post -hoc analyses. Reference: Clark R, et al. Safety and Immunogenicit y of Respiratory
Syncytial Virus Prefusion F Protein Vaccine when Co -administered with Adjuvanted Seasonal Quadrivalent Influenza Vaccine in Olde r Adults: A
Phase 3 Randomized Trial. Clin Infect Dis. 2024 Oct 15;79(4):1088 -1098. https://pubmed.ncbi.nlm.nih.gov/39099085/
2.Simultaneous administration of Moderna’s mResvia  with high -dose influenza vaccine resulted in lower RSV -A and RSV -B neutralizing antibody
titers, compared with RSV vaccination alone. Reference: https://www.cdc.gov/acip/downloads/slides -2024 -10-23-24/02 -RSV-Adult -Das-
508.pdf
12•Both vaccines include the same adjuvant system (AS01); adjuvant dose in
Shingrix is twice the dose in Arexvy .
•530 immunocompetent participants aged ≥50 years were randomized 1:1 to
receive either sequential (control group) or simultaneous (intervention
group) vaccination with Arexvy  and dose one of Shingrix, followed by
completion of the Shingrix two -dose series.GSK provided results of a co -administration study with
Arexvy  and recombinant zoster vaccine (Shingrix)
Reference: Dennis P , et al. Co -administration of the adjuvanted respiratory syncytial virus (RSV) prefusion F protein vaccine (R SVPreF3 OA) with the adjuvanted
recombinant zoster vaccine (RZV) in adults ≥50 years of age. 20th EuGMS  Congress. 2024 Sep 18 -20; Valencia, Spain.
13•Immunogenicity non -inferiority criteria were met (upper limit of 2 -sided
95% CI ≤1.5 for GMT [RSV -A or RSV -B neutralization] or GMC [anti -gE] ratio;
ratio calculated as separate administration/simultaneous administration)
-One month after Arexvy  administration, GMT ratio:
•RSV-A neutralizing antibodies: 1.14 (95% CI: 0.97, 1.35)
•RSV-B neutralizing antibodies: 0.98 (95% CI : 0.84, 1.15)
-One month after dose two of Shingrix, GMC ratio:
•Anti-gE antibodies: 1.24 (95% CI: 1.0 8, 1.42)GSK provided results of a co -administration study with
Arexvy  and recombinant zoster vaccine (Shingrix)
CI: confidence interval, GMT: geometric mean titer, GMC: geometric mean concentration
Reference: Dennis P , et al. Co -administration of the adjuvanted respiratory syncytial virus (RSV) prefusion F protein vaccine (R SVPreF3 OA) with the adjuvanted
recombinant zoster vaccine (RZV) in adults ≥50 years of age. Presented at 20th EuGMS  Congress. 2024 Sep 18 -20; Valencia, Spain.
14•No specific safety concerns identified
•Reactogenicity of simultaneous administration overall greater than that
of Arexvy  given alone, but more similar to that of Shingrix given alone
•Serious adverse events: 4.9% in simultaneous administration group vs.
2.3% in the sequential administration group, but no clustered imbalance
in any specific organ system or type of adverse event
•No cases of Guillain -Barr é syndrome (GBS) or acute disseminated
encephalomyelitis (ADEM)*GSK provided results of a co -administration study with
Arexvy  and recombinant zoster vaccine (Shingrix)
*With total enrollment of 530 participants, this trial was underpowered to detect rare adverse events.
Reference: Dennis P , et al. Co -administration of the adjuvanted respiratory syncytial virus (RSV) prefusion F protein vaccine (R SVPreF3 OA) with the adjuvanted
recombinant zoster vaccine (RZV) in adults ≥50 years of age. 20th EuGMS  Congress. 2024 Sep 18 -20; Valencia, Spain.
15•Co-administration of RSV vaccines and other recommended adult vaccines
is common.
•Given the considerable benefits of co -administration and the evidence of
safety of co -administration, the Work Group continues to feel co -
administration is acceptable .1
•In addition, the Work Group looks forward to learning more about an
analysis by Moderna on immunologic correlates of protection for RSV when
peer -reviewed publication is available.Work Group interpretations of co -administration data
1.This language is different from CDC’s General Best Practices Guidelines for Immunization, which states that with limited exce ption,
routine administration of all age -appropriate doses of vaccines simultaneously is recommended for persons for whom no specific
contraindications exist at the time of the visit.
Kroger A, Bahta  L, Long S, Sanchez P . General Best Practice Guidelines for Immunization. Best Practices Guidance of the Advisory Committee on
Immunization Practices (ACIP). https://www.cdc.gov/vaccines/hcp/imz -best -practices/ . Updated July 22, 2024; accessed October 22, 2024
16•Whether the patient is up to date with currently recommended vaccines
•The feasibility of the patient returning for additional vaccine doses
•Risk of acquiring vaccine -preventable disease
•Vaccine reactogenicity profiles
•Patient preferencesWhen deciding whether to co -administer other vaccines
with an RSV vaccine, providers may consider:
For more information, contact CDC
1-800-CDC-INFO (232 -4636)
TTY:  1 -888-232-6348    www.cdc.gov
The findings and conclusions in this report are those of the authors and do not necessarily represent the official position
of the Centers for Disease Control and Prevention.
Acknowledgements
• Adult RSV Vaccine Work Group
• CDC Coronavirus and Other Respiratory Viruses Division
• CDC Immunization Services Division

Summary: ACIP Adult RSV Work Group Clinical Considerations RSV vaccination in Adults 50 –59 at increased risk of severe  RSV diseaseDiya Surie, MD Michael Melgar, MD Amadea Britton, MD Co-Leads, Adult RSV Vaccine Work Group  Coronavirus and Other Respiratory Viruses Division (CORVD) Advisory Committee on Immunization Practices (ACIP) April 16, 2025National Center for Immunization and Respiratory Diseases  •Licensed products for use in adults aged 50 –59 years at increased risk of  severe RSV disease…


01 Asturias chikungunya 508

CHIKUNGUNYA VACCINES
ACIP Meeting
April 16, 2025
Edwin Asturias, MD
Chair, ACIP Chikungunya Vaccines Work Group
•Chikungunya Vaccines Work Group formed in May 2022
-Topics under discussion include use of chikungunya vaccines in U.S. persons at
risk of chikungunya, including those who travel abroad, laboratory workers, and
residents of U.S. territories and states at risk of transmission
•Two chikungunya vaccines
-Live attenuated vaccine licensed in November 2023 (manufactured by Valneva)
-Virus -like particle vaccine licensed in February 2025 (manufactured by Bavarian
Nordic)
-Both vaccines licensed based on immunogenicity correlates and safety, pending
clinical efficacy and expanded safety post -licensure studiesBackground
•October 2022– October 2023
-Background on chikungunya disease and its epidemiology
-Immunogenicity and safety of live attenuated chikungunya vaccine (CHIK -LA)
•February 2024
-ACIP approval of recommendations for use of CHIK -LA among U.S. travelers and
laboratory workers
•June 2024
-Epidemiology of chikungunya in U.S. territories and states
-Cost -effectiveness of use of CHIK -LA in U.S. territories
•October 2024
-Immunogenicity and safety of virus -like particle chikungunya vaccine (CHIK -VLP)Recap of previous Work Group ACIP presentations
1. Evidence to Recommendations for use of CHIK -VLP among adolescent
and adult travelers ( Vote 1 )
2. Evidence to Recommendations for use of CHIK -VLP among laboratory
workers ( Vote 2 )
3. Surveillance for adverse events following use of CHIK -LA and proposed
guidance for use and revised recommendations (Vote 3 )
4. Clinical guidance for use of CHIK -VLP among pregnant and breastfeeding
womenOverview of today’s session
Chikungunya Vaccines Work Group members
ACIP ACIP Liaisons Invited Consultants ( cont )
Edwin Asturias, Univ Colorado Elizabeth Barnett, ISTM Steven Schofield, CATMAT
Lin Chen, Mount Auburn Hosp James Campbell, AAP David Shlim, Jackson Hole Travel & Trop Med
Mary Pat Friedlander, AAFP Nestor Sosa, Uni New Mexico Hospital
CDC Lead Saroj Rai, AIM Sanet Torres, San Jorge Children & Women's Hospital
Susan Hills, DVBD Kirsten Vannice, Bill & Melinda Gates Foundation
Invited Consultants Mary Wilson, Univ California San Francisco
Ex Officio Alan Barrett, Univ Texas Galveston Joshua Wong, US Coast Guard Puerto Rico
Robin Levis, FDA Beth Bell, Univ Washington
Sixun Yang, FDA Alan Lam, DoD
Lesley Dupuy (NIH) Margaret Ryan, DoD
Chikungunya Vaccines Work Group CDC participants
DVBD DGMH ACIP Secretariat (NCIRD)
Sarah Guagliardo Kevin O’Laughlin Jessica MacNeil
Ann Powers Leslie Lee
Erin Staples DHQP
Parker Acevedo Michael McNeil
Laura Adams
GID
NCEZID Pierre Muhoza
Chris Braden

Summary: CHIKUNGUNYA VACCINES ACIP Meeting April 16, 2025 Edwin Asturias, MD Chair, ACIP Chikungunya Vaccines Work Group •Chikungunya Vaccines Work Group formed in May 2022 -Topics under discussion include use of chikungunya vaccines in U.S. persons at  risk of chikungunya, including those who travel abroad, laboratory workers, and  residents of U.S. territories and states at risk of transmission •Two chikungunya vaccines  -Live attenuated vaccine licensed in November 2023 (manufactured by Valneva)…