cdc.gov/coronavirus

Evidence to Recommendation Framework: 

Pfizer-BioNTech COVID-19 Booster Dose

Sara Oliver, MD, MSPH

ACIP Meeting

September 23, 2021
 Structure to describe information considered in moving from evidence to 

ACIP vaccine recommendations

 Provide transparency around the impact of additional factors on 

deliberations when considering a recommendation 

 Questions around vaccine policy for booster doses are complex

– Require some adaptation of our standard Evidence to Recommendation Framework

Evidence to Recommendations (EtR) Framework

2
Evidence to Recommendations (EtR) Framework

3

Standard EtR Domains

Public Health Problem

Benefits and Harms

Values

Acceptability

Feasibility

Resource Use

Equity
Evidence to Recommendations (EtR) Framework

4

Standard EtR Domains

Public Health Problem

Benefits and Harms

Values

Acceptability

Feasibility

Resource Use

Equity

Public 

Health 

Problem

Benefits 

and 

Harms

Values and 

Acceptability

Are booster 

doses 

needed?

What is the 

balance of 

benefits and 

harms for 

booster doses 

by age?

Do people 

want a booster 

dose?
Evidence to Recommendations (EtR) Framework

5

Standard EtR Domains

Public Health Problem

Benefits and Harms

Values

Acceptability

Feasibility

Resource Use

Equity

Public 

Health 

Problem

Benefits 

and 

Harms

Values and 

Acceptability

Feasibility Resource 

Use

How would 

booster doses 

be 

implemented?

What are the 

costs associated 

with booster 

doses?
Evidence to Recommendations (EtR) Framework

6

Standard EtR Domains

Public Health Problem

Benefits and Harms

Values

Acceptability

Feasibility

Resource Use

Equity

Public 

Health 

Problem

Benefits 

and 

Harms

Values and 

Acceptability

Feasibility Resource 

Use

Equity

What are equity considerations for booster doses?
Booster doses of COVID-19 vaccines

7

 Policy on booster doses will be coordinated with FDA for regulatory 

allowance, and ACIP for recommendations for use 

Review 

data 

FDA

Regulatory 

allowance

CDC/ACIP

Recommendations 

for use
 Who should be recommended to receive a Pfizer-BioNTech COVID-19 

booster dose under the current Emergency Use Authorization, based on the 

balance of benefits and risks? 

Evidence to Recommendations (EtR) Framework

Question

8
9

Public 

Health 

Problem

Evidence to Recommendations Framework

Booster doses of COVID-19 vaccines

Are booster doses of COVID-19 

vaccines needed? 
Daily trends in number of COVID-19 cases in the United 

States 

CDC. https://covid.cdc.gov/covid-data-tracker/#trends_dailycases. Accessed September 22, 2021

January 23, 2020 – September 20, 2021

10

42,234,211 total cases
Number of people fully vaccinated in the U.S. by COVID-19 

vaccine series type

CDC. https://covid.cdc.gov/covid-data-tracker/#vaccinations_vacc-total-admin-rate-total. Accessed September 22, 2021

182,012,343

Fully Vaccinated

11
0

5

10

15

20

25

30

Rate per 100,000 population

Week ending

Age-adjusted weekly COVID-19-associated hospitalization rates among adults 

by week of admission and age group*—COVID-NET, January 24–July 17, 2021

18-49 years 50-64 years ≥65 years

*Data are preliminary and case counts and rates for recent hospital admissions are subject to lag. As data are received each week, prior case counts and rates are updated accordingly.

†Cumulative rate ratio from January 24 – July 17, 2021. Shaded area indicates preliminary July data that does not include one site. 

Havers et al. https://medrxiv.org/cgi/content/short/2021.08.27.21262356v1. COVID-19-associated hospitalizations among vaccinated and unvaccinated adults ≥18 years - COVID-NET, 13 states, January 1-July 24, 2021

0

20

40

60

80

100

120

Rate per 100,000 population

Week ending

0

20

40

60

80

100

120

140

160

180

200

Rate per 100,000 population

Week ending

Vaccinated vs. Unvaccinated †

23x higher 22x higher 13x higher

12
0

0.02

0.04

0.06

0.08

0.1

0.12

Weekly COVID

May June July

-19 hospitalizations per 

1000 population

Week

18-49 50-64 65+ 60+ (Israel)*

For Israel, vaccine received in

Apr-May

Mar

Feb

Jan

Incidence among vaccinated people, for hospitalization by month in 

United States and for severe disease by time since 2nd dose in Israel

Scobie HM, Johnson AG, Suthar AB, et al. Monitoring Incidence of COVID-19 Cases, Hospitalizations, and Deaths, by Vaccination Status — 13 U.S. Jurisdictions, April 4–July 17, 2021. MMWR Morb Mortal Wkly Rep 2021;70:1284–1290. 

Goldberg et al. Waning immunity of the BNT162b2 vaccine: A nationwide study from Israel. https://www.medrxiv.org/content/10.1101/2021.08.24.21262423v1.full-text

*Israel estimates were derived from rate of severe COVID-19 (per 1,000 persons) from July 11, 2021 to July 31, 2021. 

Each data point represents all person stratified by when second dose of COVID-19 vaccine received.

13

(United States)
14

Is vaccine effectiveness (VE) waning by age? 

How do these data vary by vaccine?

Public Health Problem: 

Are booster doses of COVID-19 vaccines needed? 

Is VE waning for those with underlying medical conditions? 

Is VE waning for those with high-risk occupations? 
0

10

20

30

40

50

60

70

80

90

100

February March April May June July

Vaccine Effectiveness (%)

Nanduri et al.*

Rosenberg, et al.

Puranik, et al.

(Pfizer)

Puranik, et al.

(Moderna)

Fowlkes et al. **

Keehner, et al.**

Vaccine effectiveness against infection over time

Adults ≥18 years of age

Rosenberg ES, Holtgrave DR, Dorabawila V, et al. New COVID-19 Cases and Hospitalizations Among Adults, by Vaccination Status — New York, May 3–July 25, 2021. MMWR Morb Mortal Wkly Rep. ePub: 18 August 2021.

Nanduri S. Effectiveness of Pfizer-BioNTech and Moderna Vaccines in Preventing SARS-CoV-2 Infection Among Nursing Home Residents Before and During Widespread Circulation of the SARS-CoV-2 B.1.617.2 (Delta) Variant 

— National Healthcare Safety Network, March 1–August 1, 2021. MMWR Morbidity and Mortality Weekly Report. 2021 2021;70. 

Fowlkes A, Gaglani M, Groover K, et al. Effectiveness of COVID-19 Vaccines in Preventing SARS-CoV-2 Infection Among Frontline Workers Before and During B.1.617.2 (Delta) Variant Predominance — Eight U.S. Locations, 

December 2020–August 2021. MMWR Morb Mortal Wkly Rep. ePub: 24 August 2021. 

Puranik A, Lenehan PJ, Silvert E, et al. Comparison of two highly-effective mRNA vaccines for COVID-19 during periods of Alpha and Delta variant prevalence. medRxiv 2021.08.06.21261707. 

Keehner J, Horton LE, Binkin NJ et al. Resurgence of SARS-CoV-2 Infection in a Highly Vaccinated Health System Workforce. NEJM, September 1, 2021. DOI: 10.1056/NEJMc2112981

**HCWs, frontline workers

* Nursing Home Residents

**HCWs, first responders

15
16

Vaccine effectiveness against symptomatic infection, by 

age and time since vaccination

Source: Unpublished ICATT data, 2021
0

10

20

30

40

50

60

70

80

90

100

February March April May June July

Vaccine Effectiveness (%)

Tenforde, et al.*

Rosenberg, et al.

Puranik, et al. (Pfizer)

Puranik, et al. (Moderna)

Bajema et al.

Vaccine effectiveness against hospitalization by month

Adults ≥18 years of age

Tenforde MW, Self WH, Naioti EA, et al. Sustained Effectiveness of Pfizer-BioNTech and Moderna Vaccines Against COVID-19 Associated Hospitalizations Among Adults — United States, March–July 2021. MMWR Morb Mortal Wkly

Rep. ePub: 18 August 2021.

Tenforde MW, Olson SM, Self WH, et al. Effectiveness of Pfizer-BioNTech and Moderna Vaccines Against COVID-19 Among Hospitalized Adults Aged ≥65 Years — United States, January–March 2021. MMWR Morb Mortal Wkly Rep 

2021;70:674–679.

Rosenberg ES, Holtgrave DR, Dorabawila V, et al. New COVID-19 Cases and Hospitalizations Among Adults, by Vaccination Status — New York, May 3–July 25, 2021. MMWR Morb Mortal Wkly Rep. ePub: 18 August 2021.

Puranik A, Lenehan PJ, Silvert E, et al. Comparison of two highly-effective mRNA vaccines for COVID-19 during periods of Alpha and Delta variant prevalence. medRxiv 2021.08.06.21261707. 

Bajema KL, Dahl RM, Prill MM, et al. Effectiveness of COVID-19 mRNA Vaccines Against COVID-19–Associated Hospitalization — Five Veterans Affairs Medical Centers, United States, February 1–August 6, 2021. MMWR Morb

Mortal Wkly Rep.

* February estimates from 

platform's May 2021 MMWR

17
Vaccine effectiveness against hospitalization over time

Adults ≥16 years of age 

Bajema KL, Dahl RM, Prill MM, et al. Effectiveness of COVID-19 mRNA Vaccines Against COVID-19–Associated Hospitalization — Five Veterans Affairs Medical Centers, United States, February 1–August 6, 2021. MMWR Morb Mortal Wkly Rep.

Thompson MG, Burgess JL, Naleway AL, et al. Prevention and attenuation of Covid-19 with the BNT162b2 and mRNA-1273 vaccines. N Engl J Med 2021;385:320–9.

Self WH, Tenforde MW, Rhoads JP, et al. Comparative Effectiveness of Moderna, Pfizer-BioNTech, and Janssen (Johnson & Johnson) Vaccines in Preventing COVID-19 Hospitalizations Among Adults Without Immunocompromising Conditions — United States, 

March–August 2021. MMWR Morb Mortal Wkly Rep. ePub: 17 September 2021.

Nunes et al. mRNA vaccines effectiveness against COVID-19 hospitalizations and deaths in older adults: a cohort study based on data-linkage of national health registries in Portugal. MedRXiv preprint.

Andrews et al. Vaccine effectiveness and duration of protection of Comirnaty, Vaxzevria and Spikevax against mild and severe COVID-19 in the UK. Preprint. 

Tartof SY, Slezak JM, Fischer H, Hong V, Ackerson BK, Ranasinghe ON, et al. Six-month effectiveness of BNT162b2 mRNA COVID-19 vaccine in a large US integrated health system: a retrospective cohort study. 

https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3909743

0

20

40

60

80

100

5 weeks 10 weeks 15 weeks 20 weeks 25 weeks

Vaccine Effectivness

mRNA 16+ years

mRNA 50+ years

J&J/Janssen 16+ years

18
Summary 

Vaccine effectiveness by age

 Significant declines in VE against infection in individuals ≥65 years of age for 

mRNA products in the Delta period 

 Smaller declines in VE against hospitalization in individuals ≥65 years of age, but 

more substantial than younger populations 

 Among adults <65 years of age: vaccines remain effective in preventing 

hospitalization and severe disease

 Vaccines may be less effective in preventing infection or symptomatic illness due 

to waning over time and the Delta variant

19
20

Is vaccine effectiveness (VE) waning by age? 

How do these data vary by vaccine?

Public Health Problem: 

Are booster doses of COVID-19 vaccines needed? 

Is VE waning for those with underlying medical conditions? 

Is VE waning for those with high-risk occupations? 
Vaccine effectiveness against hospitalization among adults 

with underlying medical conditions

CDC unpublished, IVY Network

97% 98%

89% 85%

90% 85%

92% 90%

0%

20%

40%

60%

80%

100%

Pre-Delta Delta Pre-Delta Delta Pre-Delta Delta Pre-Delta Delta

No underlying condtions ≥ 1 underlying 

conditions

Hypertension Obesity

Vaccine Effectiveness

Estimates controlled for age. Excludes individuals with immunocompromising conditions. 21
Vaccine effectiveness against infection among US veterans 

with underlying conditions, pre-Delta period

22

Charlson Comorbidity Index

Butt AA, Omer SB, Yan P, Shaikh OS, Mayr FB. SARS-CoV-2 Vaccine Effectiveness in a High-Risk National Population in a Real-World Setting. Ann Intern Med. 2021;M21-1577.

98.1 96.9

0

20

40

60

80

100

Score <2 Score ≥2
Summary 

Vaccine effectiveness by underlying medical condition

 Limited data currently to evaluate VE by a variety of underlying medical conditions

– Current data with limited waning in those with at least 1 underlying medical condition

 These estimates exclude immunocompromised individuals

 Estimates may not represent effectiveness across all underlying medical conditions

– Cannot produce estimates for rare (and possibly more severe) underlying conditions

– Spectrum of underlying medical conditions with a range of severity; may have varying 

impact in effectiveness 

23
24

Is vaccine effectiveness (VE) waning by age? 

How do these data vary by vaccine?

Public Health Problem: 

Are booster doses of COVID-19 vaccines needed? 

Is VE waning for those with underlying medical conditions? 

Is VE waning for those with high-risk occupations? 
Vaccine effectiveness against infection among healthcare 

providers, first responders and frontline workers

0

20

40

60

80

100

March April May June July

Vaccine Effectiveness (%)

Fowlkes et al.

Keehner et al.

Fowlkes A, Gaglani M, Groover K, et al. Effectiveness of COVID-19 Vaccines in Preventing SARS-CoV-2 Infection Among Frontline Workers Before and During B.1.617.2 (Delta) Variant Predominance — Eight U.S. Locations, December 

2020–August 2021. MMWR Morb Mortal Wkly Rep. ePub: 24 August 2021. 

Keehner J, Horton LE, Binkin NJ et al. Resurgence of SARS-CoV-2 Infection in a Highly Vaccinated Health System Workforce. NEJM, September 1, 2021. DOI: 10.1056/NEJMc2112981 25
Summary 

Vaccine effectiveness by high-risk occupation 

 Effectiveness among healthcare and other frontline essential workers are similar 

to estimates for general population of the same age 

 Severe disease among vaccinated essential workers is rare

 Vaccine effectiveness waning against infections in this population

– Impact of lower VE against infections may be different among healthcare and other 

frontline essential workers

 Many prioritized for earlier doses of COVID-19 vaccines

– Longer duration since primary series

26
27

Is vaccine effectiveness (VE) waning by age? 

How do these data vary by vaccine?

Public Health Problem: 

Are booster doses of COVID-19 vaccines needed? 

Is VE waning for those with underlying medical conditions? 

Is VE waning for those with high-risk occupations? 
0

20

40

60

80

100

Summary of VE estimates since introduction of the Delta variant

Adults ≥18 years of age

See reference list in later slides

mRNA vaccines COMBINED Pfizer-BioNTech vaccine Moderna vaccine Janssen vaccine

Infection/Symptomatic infection

Hospitalization/severe disease

28
Summary 

Vaccine effectiveness by vaccine

 Vaccine effectiveness varies by initial vaccine type 

 Protection against hospitalization for mRNA vaccines high

 Protection against infection is lower for all vaccines

29
Summary

 Hospitalization rates are ~10X-22X higher in unvaccinated as compared to 

vaccinated adults

 Over 182 million people are fully vaccinated in the U.S.

 Although COVID-19 continues to be a public health problem, among persons who 

have received a primary series, data support continued protection against 

hospitalizations and deaths

– Need to follow data around long-term outcomes among infections after vaccination

30
Benefits 

and 

Harms

Evidence to Recommendations Framework

Booster doses of COVID-19 vaccines

What is the balance of benefits and 

harms for booster doses by age?

31
32

Are booster doses of the COVID-19 vaccine safe and immunogenic

(GRADE)? 

What is the benefit/risk assessment by age?

What is the summary of benefits and harms by age and population? 

Benefits and Harms: 

What is the balance of benefits and harms for 

booster doses by age? 
33

PICO Question

Population Persons aged ≥18 years who completed a COVID-19 vaccine 

primary series ≥6 months ago

Intervention Pfizer-BioNTech COVID-19 Vaccine BNT162b2 booster dose 

(30 μg, IM)

Comparison No booster dose

Outcomes Symptomatic laboratory-confirmed COVID-19

Hospitalization due to COVID-19

Death due to COVID-19

Transmission of SARS-CoV-2 infection

Serious adverse events

Reactogenicity
Evidence retrieval

34

Records identified from 

WHO/IVAC literature 

review*

(n = 2)

Additional records identified 

through other sources**

(n = 2)

*See https://view-hub.org/resources

** Phase 1 and Phase 2/3 Clinical Trail 

results from clinicaltrials.gov and other

Records excluded 

from initial review

(n = 0)

Records screened

(n = 4)

Records assessed 

for eligibility

(n = 4) Full-text articles 

excluded 

(n = 0) Records included in evidence 

synthesis (n = 4)

2 randomized trial records

2 vaccine effectiveness 

studies

Articles were eligible for inclusion if published or 

available on a pre-print server before 9/20/21.

-Criteria included in the ongoing systematic review 

conducted by the International Vaccine Access 

Center (IVAC) and the World Health Organization
Observational studies from Israel (n=2)

 Delta variant became dominant in Israel in mid-June 

 Israel authorized a 3rd dose for immunocompromised residents on July 12, 2021, 

and for all residents ≥60 years on July 30, 2021

 Two studies have assessed the effectiveness of a 3rd dose:

 Large studies: Data extracted from Ministry of Health national database or 

large health system database

 Time since 2nd dose: ≥5 months

 Control population: individuals that completed the 2 dose series

Cylus, J., Panteli, D. & van Ginneken, E. Who should be vaccinated first? Comparing vaccine prioritization strategies in Israel and European countries using the Covid-19 Health System Response Monitor. Isr J 

Health Policy Res 10, 16 (2021).

Bar-O et al. BNT162b2 vaccine booster dose protection: A nationwide study from Israel. medRxiv preprint Autust 31, 2021. doi: https://doi.org/10.1101/2021.08.27.21262679

Patalon et al. Short Term Reduction in the Odds of Testing Positive for SARS-CoV-2; a Comparison Between Two Doses and Three doses of the BNT162b2 Vaccine. MedRxiv, August 31, 2021 35
Observational studies from Israel (n=2)

Bar-On YM, Goldberg Y, Mandel M, et al. Protection of BNT162b2 Vaccine Booster against Covid-19 in Israel [published online ahead of print, 2021 Sep 15]. N Engl J Med. 2021;10.1056/NEJMoa2114255.

Patalon et al. Short Term Reduction in the Odds of Testing Positive for SARS-CoV-2; a Comparison Between Two Doses and Three doses of the BNT162b2 Vaccine. MedRxiv, August 31, 2021

July 

25

26 27 28 29 30 31

Aug 1 2 3 4 5 6 7

8 9 10 11 12 13 14

15 16 17 18 19 20 21

22 23 24 25 26 27 28

29 30 31 Sept 

1

2 3 4

Documented Infection

July 

25

26 27 28 29 30 31

Aug 1 2 3 4 5 6 7

8 9 10 11 12 13 14

15 16 17 18 19 20 21

22 23 24 25 26 27 28

29 30 31 Sept 

1

2 3 4

follow up period 

exclusion window

Both 3rd dose studies have short follow up 

periods, with a maximum of 21 days for 

documented infection and 16 days for 

severe disease

36

July 

25

26 27 28 29 30 31

Aug 1 2 3 4 5 6 7

8 9 10 11 12 13 14

15 16 17 18 19 20 21

22 23 24 25 26 27 28

29 30 31 Sept 

1

2 3 4

Severe Disease

Patalon et al.

Bar-On et al.
Location Study Population Methoda Time period 

(dominant 

variant)

Days 

after 

booster 

dose

Control

Group

Outcome Booster 

vaccinees

n/N

(or person-time)

Dose 2 vaccinees

n/N

(or person-time)

Incremental VE

(booster dose 

vs. dose 2)

95% CI

Israela Bar-On,

September

2021

General 

population ≥60 

years

Retrospective 

Cohort

7/30–8/31/21

(Delta)

≥12 Dose 2 Any 

infection

934 infections / 

10,603,410 persondays

4,439 infections / 

5,193,825 persondays

91.2%b 90.4–91.9%

Israela Patalon,

August 2021

(preprint)

General 

population ≥40 

years

Test Negative 

Design

8/1–8/21/21

(Delta)

14–20 Dose 2 Any 

infection

1,188 positive / 

32,697 total tests

8.285 positive / 

149,379 total tests

79%c 72–84%

Matched caseControl

NR/30,295 booster 

vaccinees

NR/238,018 dose 2 

vaccinees

70%c 62–76%

Outcome 1: Symptomatic laboratory-confirmed COVID-19

observational studies with dose 2 comparison group (n=2)

NR: Not reported VE: vaccine effectiveness CI: confidence intervals

a. A minimum interval of 5 months after the 2nd dose is required to be eligible for the BNT162b2 booster dose in Israel. Israeli authorities approved a booster dose for “high riskpopulations” on 7/12/21 and for persons aged ≥60 years on 7/30/21.

b. VE was calculated from the rate ratio reported in the manuscript. Rate ratio calculated using a Poisson regression model, adjusted for age (60–69, 70–79, ≥80), 

gender, demographic group (General Jewish, Arab, ultra-Orthodox Jewish), date of second vaccine dose (in half-month intervals), and calendar date.

c. VE calculated from odds ratios (and 95% CI) from logistic regression models, adjusted for 10-year age category, sex, time since vaccination category, comorbidities, and log number 

of positive tests.

37
38

Certainty assessment No of patients Effect

No of Certainty Importance

studies

Study 

design

Risk of 

bias Inconsistency Indirectness Imprecision Other considerations

Pfizer BioNTech 

COVID-19 Vaccine, 

30 mcg, booster 

dose

Pfizer BioNTech 

COVID-19 

Vaccine, 30 mcg, 

dose 2

Relative

(95% CI)

Absolute

(95% CI)

Vaccine efficacy against symptomatic COVID-19

2 RCT Very 

seriousa

Not serious Very seriousb Seriousc None For Phase 2/3 trial participants aged 18-55, the ratio of geometric mean titers (GMT) 

of neutralizing antibodies at 1 month after booster dose (2,476.4 [2210.1, 2,774.9]) 

was noninferior to the GMT detected at 1 month after dose 2 (753.7 [95% CI 658.2, 

863.1]). The geometric mean ratio was 3.29 (95% CI 2.76-3.91). Noninferiority was 

declared because the lower bound of the 2-sided 97.5% CI for the GMR is > 0.67 and 

the point estimate of the GMR is >=0.8.d For Phase 1 trial participants aged 65-85, 

the ratio of geometric mean titers (GMT) of neutralizing antibodies at 1 month after 

booster dose (1612.7 [875.5,2970]) was higher than the GMT detected at 1 month 

after dose 2 (195.8 [95% CI 114.7, 334.4]). The geometric mean ratio was 8.2 (95% 

CI for the point estimates do not overlap).d

Type 4 CRITICAL

1e Obs Not 

serious

Not serious Very seriousf Not serious None 934/1,137,804 

(0.0%)g

4,439/1,137,804 

(0.4%)h

RR 0.09

(0.08 to 

0.10)

277 fewer 

per 100,000 

(from 290 to 

275 fewer)

Type 4 CRITICAL

CI: Confidence interval; RR: Risk ratio

a. Concern for very serious risk of bias was present. Although a non-random subset of participants from the phase 3 trial were randomized to a booster dose or another investigational vaccine, none were randomized to a placebo, the only data available 

for GRADE were from a pre-post booster analysis.

b. Very serious concern for indirectness was noted because efficacy is inferred from immunobridging to the same participants after dose 2 of Pfizer-BioNTech COVID-19 vaccine, and because immunogenicity data were primarily for participants aged 18–55 years, 

which might not be representative of older participants.

c. Serious risk of imprecision was noted because number of study participants did not meet optimal information size.

d. Seroresponse was also assessed for noninferiority. 197/198 participants (99.5%) in the booster trial had a seroresponse at 1 month after booster dose, and 194/198 (98%) had a seroresponse at 1 month after dose 1, for a 1.5% difference (95% CI -0.7–3.7%). 

Noninferiority was declared because the lower bound of the 2-sided CI for the % difference is greater than -10. Seroresponse was not reported for Phase 1 trail participants.

e. The results of one study are shown. A second study (preprint) provided results for any SARS-C0V-2 infection, with a study population that overlapped with the included study, therefore results were not pooled. The additional study used test-negative design,

and indicated a vaccine effectiveness of 79% (95% CI 72%-84%) for the booster dose compared to the primary series. This corresponds to a relative risk of 0.21 (95% CI 0.16–0.28).

f. Very serious concern for indirectness was noted. The outcome of the study was any SARS-CoV-2 infection, which was an indirect measure of the PICO outcome of symptomatic COVID-19. The short duration of follow-up likely limited assessment of VE.

g. The number of participants who received the booster dose was not known. The study population included 1,137,804 persons, who contributed 10,603,410 person-days to the booster cohort (≥12 days after booster; ≥ 5 months after dose 2).

h. The number of participants who did not receive the booster dose was not known. The study population included 1,137,804 persons, who contributed 5,193,825 person-days to the no booster cohort (2 vaccine doses).

Evidence Table: Symptomatic laboratory-confirmed COVID-19
Evidence Table: Hospitalization due to COVID-19 

39

Certainty assessment No of patients Effect

Certainty No of Importance

studies Study 

design

Risk of 

bias

Inconsistency Indirectness Imprecision Other 

considerations

Pfizer 

BioNTech 

COVID-19 

Vaccine, 30 

mcg, booster 

dose

Pfizer 

BioNTech 

COVID-19 

Vaccine, 30 

mcg, dose 2

Relative

(95% CI)

Absolute 

(95% CI)

Vaccine efficacy against hospitalization due to COVID-19 

1 Obs not serious not serious very seriousa not serious none 29/1,137,804 

(0.0%)b

294/1,137,804 

(0.0%)c

RR 0.05

(0.03 to 

0.08)

26 fewer 

per 

100,000 

(from 27 

to 25 

fewer)

Type 4 CRITICAL

a. Very serious concern for indirectness was noted. The outcome of the study was severe COVID-19, which was an indirect measure of the PICO outcome of hospitalization for COVID-19. The short 

duration of follow-up likely limited an accurate assessment of VE.

b. The number of participants who received the booster dose was not known. The study population included 1,137,804 persons, who contributed 6,265,361 person-days to the booster cohort (≥12 

days after booster; ≥ 5 months after dose 2).

c. The number of participants who did not receive the booster dose was not known. The study population included 1,137,804 persons, who contributed 4,574,439 person-days to the no booster 

cohort (2 vaccine doses).

CI: Confidence interval; RR: Risk ratio
Evidence Table: Harms

CI: Confidence interval; RR: Risk ratio 40

Certainty assessment No of patients Effect

No of Certainty Importance

studies

Study 

design Risk of bias Inconsistency Indirectness Imprecision Other considerations

Pfizer BioNTech 

COVID-19 

vaccine, 30 

mcg, booster

no booster Relative

(95% CI)

Absolute

(95% CI)

Serious adverse events (follow up: median 2 months)

1 randomized 

trials

very serious 

a,b

not serious seriousc very seriousd none 1/306 (0.3%)e 43/10841 

(0.4%)b

RR 0.82

(0.11 to 5.96)

71 fewer per 

100,000

(from 353 fewer to 

1,967 more)

Type 4 CRITICAL

Reactogenicity, grade >=3

1 randomized 

trials

very serious 

a,f

not serious seriousc seriousg none 19/289 (6.6%) 362/4108 

(8.8%)f

RR 0.62

(0.40 to 0.97)

3,349 fewer per 

100,000

(from 5,287 fewer 

to 264 fewer)

Type 4 IMPORTANT

a. Very serious risk of bias; although a non-random subset of participants from the phase 3 trial were randomized to a booster dose or another investigational vaccine, the only booster trial data available for 

GRADE were not according to randomization.

b. Comparison group is safety population, subgroup aged 16–55 years, with blinded follow-up from dose 1 to 1 month after dose 2, at the time of the data cut-off date for the Biologics Licensure Application to the FDA 

(March 13, 2021). Not all persons in the comparison group received two doses.

c. Serious concern for indirectness was noted because participants were restricted to persons aged 18–55 years and might not be representative of older participants.

d. Very serious concern for imprecision was present because the number of study participants did not meet optimal information size, and the 95% CIs for the relative and absolute risks include both benefits and harms.

One event was observed among persons who received a booster dose. 

e. One serious adverse event, a myocardial infarction, occurred 62 days after dose 3. This was judged by investigators to be unrelated to the intervention.

f. Comparison group based on any grade 3 reaction reported in all participants post dose 1 or 2, at the time of the data analysis prior to the Biologics Licensure Application to the FDA (March 13, 2021). 

g. Serious risk of imprecision was noted because number of study participants did not meet optimal information size.
Lymphadenopathy was more common after the 3rd dose than 

after the 2nd dose

Clinical trial data requested by CDC. 41

 16/306 participants (5.2%) in the Phase 3 trial (adults 18–55 years) 

reported lymphadenopathy

– All 16 subjects had axillary lymphadenopathy

– One subject also had lymphadenopathy reported in the neck

– One severe event of lymphadenopathy was reported by 1 participant (onset 

of 2 days post-booster), recovered/resolved 5 days from onset

 Lymphadenopathy was observed more frequently following the booster 

dose than after primary series doses (5.2% compared to 0.4%)
Safety data regarding 3rd dose Pfizer-BioNTech COVID-19 

vaccination, Israel

https://www.fda.gov/media/152205/download 42

 3rd doses became authorized for all adults ≥60 years on July 30, 2021

– Expanded to ≥12 years at the end of August

 ~2.8 M 3rd doses administered to persons ≥12 years (through September 13)

– Most to persons ≥60 years 

 Rates of reported systemic, local, neurologic, allergic, and other reactions were 

substantially lower after dose 3 than after dose 1 or 2. Suspected under-reporting

 1 case of myocarditis in individual ≥30 years of age

– Due to limited follow up time, unable to determine rates of myocarditis in younger 

adults from Israeli data available to date 
Summary of GRADE

OutcomeImportance Design

(# of studies)

FindingsEvidence

type

Benefits

Symptomatic 

laboratory-confirmed 

COVID-19

Critical RCT (2)

OBS (1)

Pfizer-BioNTech COVID-19 booster dose induced immune responses 

(GMR, seroresponse) noninferior to those following dose 

2. Observational data suggest increased protective effect against any 

SARS-CoV-2 infection.

4

Hospitalization due to 

COVID-19

Critical RCT (0)

OBS (1)

Observational data suggest increased protective effect against severe 

COVID-19. 4

Death due to COVID-19 Important RCT (0)

OBS (0) No data available. ND

Transmission of SARSCoV-2 infection Important OBS (0) No data available. ND

Harms

Serious adverse eventsCritical RCT (1) No SAEs were attributed to booster dose. 4

Reactogenicity Important RCT (1) Grade ≥3 reactogenicity was reported by 6.6% of booster dose 

recipients.

4

Evidence type: 1=high; 2=moderate; 3=low; 4=very low; ND, no data 43
44

Are booster doses of the COVID-19 vaccine safe and immunogenic

(GRADE)? 

What is the benefit/risk assessment by age?

What is the summary of benefits and harms by age and population? 

Benefits and Harms: 

What is the balance of benefits and harms for 

booster doses by age? 
Number needed to vaccinate with booster dose to prevent 

one hospitalization over 6 months

45

8738

3361

2051

481

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

18-29 30-49 50-64 65+

Number needed to vaccinate to prevent one 

hospitalization

Age groups (years)
46

0

33

63

90

0

58

111

160

200 150 100 50 0

Benefits and risks after Pfizer-BioNTech COVID-19 vaccination for 

persons aged 18 – 29 years, by sex

95%

90%

85%

80%

For every million doses of vaccine given

1https://www.cdc.gov/mmwr/volumes/70/wr/mm7037e1.htm?s_cid=mm7037e1_w. 

Pre-Booster 

VE

0 50 100 150 200

24

24

24

24

2

2

2

2

Cases of Myocarditis Among Males & 

Females Expected per Million Doses

COVID-19-Associated Hospitalizations Among 

Males & Females Prevented per Million Doses

Benefit/risk balance among younger population varies by sex, VE after booster dose, 

rates of myocarditis, and incidence. 

As incidence declines, more uncertainty around the balance of benefits and risks
Summary 

Benefit/risk assessment

 Risks of myocarditis after a 3rd dose of mRNA vaccines is unknown

– After 2nd dose, risk varies by age and sex

 Benefit/risk balance is the most favorable for adults ≥65 years of age using current 

estimates of vaccine effectiveness 

 Benefit/risk balance among younger population varies by sex, VE after booster 

dose, rates of myocarditis, and incidence. As incidence declines, more uncertainty

around the balance of benefits and risks

47
48

Are booster doses of the COVID-19 vaccine safe and immunogenic

(GRADE)? 

What is the benefit/risk assessment by age?

What is the summary of benefits and harms by age and population? 

Benefits and Harms: 

What is the balance of benefits and harms for 

booster doses by age? 
Summary-balance of benefits and harms for booster doses 

 Data from clinical trial limited in size (n~300) and age (primarily 18-55 years)

 Booster dose of Pfizer-BioNTech COVID-19 vaccine increases immune response in 

those who have completed a primary series approximately 6 months previously

 Individual benefit/risk balance varies by age 

– Largest benefit from vaccination of individuals ≥65 years of age

– Benefit to other ages incrementally smaller, given higher VE maintained from primary series

– Even within age categories, likely variation within balance of benefits and risks given risk of 

exposure, medical condition and sex

 Unable to account for other benefits

– Possible impact on rates of community transmission

49
50

Values and 

Acceptability

Evidence to Recommendations Framework

Booster doses of COVID-19 vaccines

Do people want a booster dose?
Values and Acceptability

 In published surveys completed in August (n=5), 76%-87% of vaccinated 

adults reported they would get a booster dose, if available1-5

– In one survey, this increased to 93% of surveyed adults if it was recommended 

by their primary care provider

1. Axios Ipsos Poll. August 2, 2021.

2. Axios Ipsos Poll. August 30, 2021.

3. Marist Poll. September 3, 2021. https://maristpoll.marist.edu/polls/npr-pbs-newshour-marist-national-poll-covid-september-3-2021/

4. Morning Consult Poll. August 25, 2021. https://morningconsult.com/2021/08/25/covid-booster-shot-poll/

5. Reuters/Ipsos Poll. September 1, 2021. https://www.reuters.com/business/healthcare-pharmaceuticals/most-vaccinated-americans-want-covid-19-booster-shots-reutersipsos-poll-2021-09-01/ 51
0.4%

1.8%

2.1%

3.8%

6.1%

10.0%

12.1%

63.8%

0% 10% 20% 30% 40% 50% 60% 70%

Refused to answer

Already received booster

Definitely not

Only if required for work/school

Don't know

Wait to see if booster is safe

Wait to see if booster works

Get booster ASAP

% of vaccinated respondents

Around 2/3 of vaccinated respondents said they would get a 

COVID-19 booster vaccine

CDC/University of Iowa unpublished data, August 2021 52
0.7%

12.5%

25.0%

6.1%

40.0%

9.4%

6.2%

0% 5% 10% 15% 20% 25% 30% 35% 40% 45%

Refuse to answer

Don't know

Much less likely

Less likely

No impact

More likely

Much more likely

% of respondents

Around 1/3 of unvaccinated respondents said that COVID-19 booster 

vaccines would make them less likely to get vaccinated at all 

CDC/University of Iowa unpublished data, August 2021 53
70.9%

67.0% 65.8%

57.3% 56.4% 56.4%

35.3%

23.7% 21.6%

18.3%

24.5% 24.3%

30.0%

32.6%

29.5%

47.8%

39.1%

50.3%

10.9%

8.5% 9.8%

12.7% 11.0%

14.1% 16.9%

37.1%

28.1%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Healthcare

workers

Care facility

residents

Aged >=75 Essential

workers

Aged 65-74 Other countries Aged 50-64 Aged 12-17 Aged 18-49

% of respondents who chose response option

High Medium Low

At least 2/3 of respondents believed that healthcare workers, 

LTCF residents and adults ≥75 should be prioritized for booster doses

CDC/University of Iowa unpublished data, August 2021

54
70.9%

67.0% 65.8%

57.3% 56.4% 56.4%

35.3%

23.7% 21.6%

18.3%

24.5% 24.3%

30.0%

32.6%

29.5%

47.8%

39.1%

50.3%

10.9%

8.5% 9.8%

12.7% 11.0%

14.1% 16.9%

37.1%

28.1%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Healthcare

workers

Care facility

residents

Aged >=75 Essential

workers

Aged 65-74 Other countries Aged 50-64 Aged 12-17 Aged 18-49

% of respondents who chose response option

High Medium Low

Over half felt that essential workers, adults aged 65–74 years of age 

and other countries should be recommended for booster doses 

CDC/University of Iowa unpublished data, August 2021

55
70.9%

67.0% 65.8%

57.3% 56.4% 56.4%

35.3%

23.7% 21.6%

18.3%

24.5% 24.3%

30.0%

32.6%

29.5%

47.8%

39.1%

50.3%

10.9%

8.5% 9.8%

12.7% 11.0%

14.1% 16.9%

37.1%

28.1%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Healthcare

workers

Care facility

residents

Aged >=75 Essential

workers

Aged 65-74 Other countries Aged 50-64 Aged 12-17 Aged 18-49

% of respondents who chose response option

High Medium Low

Adults ≤64 years were the least prioritized groups for booster doses

CDC/University of Iowa unpublished data, August 2021

56
Summary

Values and Acceptability 

 At least 2/3 of vaccinated adults willing to receive a booster dose

 Survey respondents prioritized older adults and healthcare workers for 

booster doses; younger adults less prioritized 

57
58

Feasibility 

and 

Implementation

Evidence to Recommendations Framework

Booster doses of COVID-19 vaccines

How would booster doses be 

implemented?
Completed primary vaccination series by week 

0

2

4

6

8

10

12

14

12/19/2020 1/19/2021 2/19/2021 3/19/2021 4/19/2021 5/19/2021 6/19/2021 7/19/2021 8/19/2021

Millions

J&J Moderna Pfizer

59
0

1

2

3

4

5

12/19/2020 1/19/2021 2/19/2021 3/19/2021 4/19/2021 5/19/2021 6/19/2021 7/19/2021 8/19/2021 Millions

Pfizer Moderna J&J

Completed primary vaccination series by week:

Adults ≥65 years of age

60
0

1

2

3

4

5

12/19/2020 1/19/2021 2/19/2021 3/19/2021 4/19/2021 5/19/2021 6/19/2021 7/19/2021 8/19/2021 Millions

Pfizer Moderna J&J

Completed primary series 6 months prior 

Completed primary vaccination series by week:

Adults ≥65 years of age

61
0

1

2

3

4

5

Millions

0

1

2

3

4

5

Millions

0

1

2

3

4

5

12/19/2020 1/19/2021 2/19/2021 3/19/2021 4/19/2021 5/19/2021 6/19/2021 7/19/2021 8/19/2021

Millions

Completed Completed primary vaccination series by week and age

50-64 years

30-49 years

18-29 years

62
0

1

2

3

4

5

Millions

0

1

2

3

4

5

Millions

0

1

2

3

4

5

12/19/2020 1/19/2021 2/19/2021 3/19/2021 4/19/2021 5/19/2021 6/19/2021 7/19/2021 8/19/2021

Millions

Completed Completed primary vaccination series by week and age

50-64 years

30-49 years

18-29 years

63

Completed primary series 6 months prior 
Number of persons eligible (in millions) for a booster 

dose on September 27th, 2021

≥6 months after primary series

Age group Pfizer-BioNTech Moderna Janssen/J&J Total

18-29 years old 2.0 1.5 0.3 3.9

30-49 years old 5.5 4.4 0.9 10.8

50-64 years old 5.3 4.4 1.2 11.0

65+ years old 13.6 12.9 0.8 27.4

Total 26.4 23.4 3.3 53.0

64
65

 Jurisdictions have begun preparing for implementation of booster doses

 Booster doses likely given in a variety of settings: pharmacies, providers offices, 

health departments, occupational clinics and federal programs (e.g., LTCF 

program)

– Over 70% of current COVID-19 vaccine administration occurring in pharmacies

 Many jurisdictions experiencing surge in cases of COVID-19, outreach for 

unvaccinated individuals to receive primary series, fall/winter influenza campaigns

Jurisdictional preparations
66

 3 vaccines are currently being administered in the United States

 For additional doses of mRNA vaccines in immunocompromised persons, the 

current recommendations state that the additional dose should be the same 

product as the primary series. 

– If the product given for the first 2 doses is not available, the other vaccine product may 

be administered

 Evidence reviewed by FDA only evaluated a booster dose of Pfizer-BioNTech 

vaccine after completion of a Pfizer-BioNTech primary series

Implementation

Variation in primary series receipt
67

 LTCFs can arrange for an on-site vaccination clinic or help residents access 

vaccine in local community

– Federal LTCF program can help implement vaccination in long-term care settings

 8.1 million doses administered during original LTCF program (December 2020-

March 2021): 6.2M (76%) were Pfizer-BioNTech, 1.9M (24%) were Moderna

 LTCFs can have substantial turnover over time: 

– 30% per month for residents

– 100% per year for staff 

Implementation

Long-term care facility (LTCF) residents
68

 Current CDC clinical considerations state: 

“For public health purposes, immunocompromised people who have completed 

a primary vaccine series (i.e. 2-dose mRNA vaccine series or a single dose of the 

Janssen vaccine) are considered fully vaccinated ≥2 weeks after completion of 

the primary series” 

 Based on current data, the definition of ‘fully vaccinated’ would remain the 

same after recommendations for booster dose

– Fully vaccinated ≥2 weeks after completion of the primary series

Implications for public health recommendations 

Definition of ‘fully vaccinated’

https://www.cdc.gov/vaccines/covid-19/clinical-considerations/covid-19-vaccines-us.html
Summary - Feasibility and Implementation

 To date, >220 million doses of Pfizer-BioNTech Covid-19 vaccine have been 

administered in the U.S., demonstrating that the vaccine is feasible to implement

– ~2.24 million individuals have received an additional dose

 Over 27 million adults ≥65 years of age completed their primary series ≥6 months 

ago

– Over 50 million adults ≥18 years of age completed their primary series ≥6 months ago

 Pharmacies delivering majority of COVID-19 vaccines currently

 Recommendations that are clear and simple will facilitate implementation

69
70

Resource 

Use

Evidence to Recommendations Framework

Booster doses of COVID-19 vaccines

What is the cost associated with 

booster doses?
 All COVID-19 vaccines, including booster doses, will be provided free of charge to 

the U.S. population. However, health systems or health departments could incur 

costs for vaccination program planning and implementation

 Fees for administration of COVID-19 vaccines recommended by ACIP are 

reimbursable by insurance or other federal programs 

 Cost effectiveness analyses will be important in the future, when vaccine not 

purchased and distributed by the federal government 

Summary - Resource Use

71
72

Equity

Evidence to Recommendations Framework

Booster doses of COVID-19 vaccines

What are the equity considerations 

with booster doses?
30.2

51.2

98.5

124.9

133.4

221.1

0 50 100 150 200 250

Asian

White

Hispanic

NH/PI

Black

AI/AN

Excess death incidence rate per 100,000 person-years

Annual excess death incidence rates for persons aged 25-64 

years by race/ethnicity – United States, 2020

Rossen LM, Ahmad FB, Anderson RN, et al. Disparities in Excess Mortality Associated with COVID-19 — United States, 2020. MMWR Morb Mortal Wkly Rep 2021;70:1114–

1119. DOI: http://dx.doi.org/10.15585/mmwr.mm7033a2 73
Cumulative COVID-19 associated hospitalizations in the United 

States by race/ethnicity, March 7, 2020 – September 11, 2021

CDC. https://covid.cdc.gov/covid-data-tracker/#covidnet-hospitalization-network. Accessed September 21, 2021

American Indian/Alaska Native: 1273.8

Black: 1.009.5

Hispanic: 816.5

Overall: 654

White: 486

Asian/Pacific Islander: 346

74
What percentage of people in each race or ethnic group 

received at least one dose of COVID-19 vaccine?

CDC. https://covid.cdc.gov/covid-data-tracker/#vaccination-demographics-trends. Accessed September 21, 2021

34.6%

40.7%

41.8%

43.2%

46.2%

56.1%

0% 10% 20% 30% 40% 50% 60%

Black

White

Hispanic/Latino

Asian

NH/PI

AI/AN

75
Percentage of people who have received at least one dose 

of the COVID-19 vaccine by race/ethnicity over time

CDC. https://covid.cdc.gov/covid-data-tracker/#vaccination-demographics-trends as of September 20, 2021, and US Census Bureau National Population Estimates

0

10

20

30

40

50

60

Dec-20 Jan-21 Feb-21 Mar-21 Apr-21 May-21 Jun-21 Jul-21 Aug-21 Sep-21

AI/AN

Asian

Black

Hispanic/Latino

NHOPI

White

76
Vaccine effectiveness by race and ethnicity

M Thompson et al. NEJM https://www.nejm.org/doi/pdf/10.1056/NEJMoa2110362?articleTools=true

 Among VE platforms able to provide specific estimates for vaccine 

effectiveness by race or ethnicity, no differences noted 

 VE against hospitalization among adults ≥50 years of age: 

– Overall: 89% (95% CI: 87-91%)

– Black individuals: 86% (95% CI: 75-92%)

– Hispanic individuals: 90% (95% CI: 85-93%)

 VE against hospitalization among VA centers: 

– Black individuals: 86% (95% CI: 77-93%)

– White individuals: 88% (95% CI: 77-94%)

77
Summary - Equity

 COVID-19 disease and COVID-19 vaccination varies by socioeconomic and 

sociodemographic groups

– However, vaccine effectiveness does not vary by race and ethnicity

 Equity gap in vaccines administered by race is closing

– Disparities were more pronounced this spring (individuals who would be 6 

months after 2nd dose)

78
Summary 
Work Group Interpretation 

 Top priority should be continued vaccination of unvaccinated individuals

 Jurisdictions have a variety of vaccination and disease control priorities 

– E.g. COVID-19 cases, delivery of primary COVID-19 vaccines series and influenza vaccines

 Balance of benefits and risks varies by age

– Adults ≥65 years have the clearest benefit/risk

– Benefit to other age groups incrementally smaller, given high effectiveness maintained from 

primary series

Goals of booster program:

 Prevention of severe disease 

 Other considerations are important, such as maintaining workforce and healthcare capacity, 

prevention of transmission, individual benefit/risk balance

80
Clinical Considerations 
82

Evidence to Recommendations Framework

Summary: Work Group Interpretations

Type of 

recommendation

We do not recommend the 

intervention

We recommend the 

intervention for individuals 

based on assessment of 

benefits and risks

We recommend the 

intervention 

Used when the risks

clearly outweigh the 

benefits

in a population

Used when the 

benefits clearly 

outweigh the risks 

in a population

Used when there is 

diversity of the 

benefits and risks 

in a population

Can allow flexibility

across a population
83

Policy Options

Policy question #1: 

Should adults ≥65 years of age and LTCF residents receive a Pfizer-BioNTech 

COVID-19 vaccine booster dose?
84

Policy Options

Policy question #1: 

Should adults ≥65 years of age and LTCF residents receive a Pfizer-BioNTech 

COVID-19 vaccine booster dose?

Policy question #2: 

Should adults 18–64 years of age at risk for severe COVID-19 due to underlying

medical conditions or at risk of SARS-CoV-2 exposure due to occupation/setting 

receive a Pfizer-BioNTech COVID-19 vaccine booster dose?
85

PROS CONS

• Highest risk of severe disease

• Largest impact in waning VE against severe 

disease

• Prioritized for early doses of COVID-19 vaccines 

(longer duration since primary series)

Age cut-off may not represent 

continuum of risk

Policy Question #1

Adults ≥65 years of age and LTCF residents
86

Policy Question #2

Adults 18–64 years of age at risk for severe COVID-19 due to underlying medical 

conditions or at risk of SARS-CoV-2 exposure due to occupation/setting

Type of 

recommendation PROS CONS

Standard 

recommendation

• Simple

• Reduces barriers for individuals who 

may have increased risk of disease

• Reduction in infection could reduce 

work absenteeism 

• Not strong evidence of increased risk of 

hospitalization or death in all individuals

• Balance of benefits and risks likely varies

• Large number of people initially eligible 

(>50 million)

Recommended for 

individuals based 

on assessment of 

benefits and risks

• Reduces barriers for individuals who 

may have increased risk of disease

• Reduction in infection could reduce 

work absenteeism 

• Reflects uncertainty in current balance 

of benefits and risks in this population

• Large number of people initially eligible 

(>50 million)

• More complicated to implement
 Monica Godfrey

 Jack Gersten

 Amy Blain

 Heidi Moline

 Danielle Moulia

 Kathleen Dooling 

 Megan Wallace

 Jennifer Collins

 Jefferson Jones

 Julia Gargano

 Eddie Shanley

 Stephen Hadler

 Hannah Rosenblum

 Heather Scobie

 Ian Plumb

 Amy Blain

 Neela Goswami

 Mary Chamberland

 CDC/University of Iowa

 VTF ACIP WG Team

 ACIP COVID-19 Vaccines Work Group

 Vaccine Task Force

 Epi Task Force

 Respiratory Viruses Branch

Acknowledgments
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.

Thank you