06 Melgar Surie adult rsv 508

CDC ACIP — Vaccine Advisory Committee

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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