COVID-19 Vaccine Safety Technical (VaST) 

Work Group 

Safety Assessment 

H. Keipp Talbot, MD MPH (VaST Chair)

Robert H. Hopkins, Jr., MD (NVAC Chair)

Advisory Committee on Immunization Practices

November 19, 2021
COVID-19 Vaccine Safety Technical (VaST) Work Group

Objectives

 Review, evaluate, and interpret post-authorization/approval COVID-19 

vaccination safety data

 Serve as the central hub for technical subject matter expertise from federal 

agencies conducting post-authorization/approval safety monitoring

 Advise on analyses, interpretation, and presentation of vaccine safety data

 Provide updates to the ACIP COVID-19 Vaccines Work Group and the entire 

ACIP on COVID-19 vaccine safety

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VaST continues to review COVID-19 vaccination safety 

data from passive and active surveillance systems

 U.S. safety monitoring systems including Vaccine Adverse Events 

Reporting System (VAERS), Vaccine Safety Datalink (VSD), FDA BEST 

System,1 Department of Veterans Affairs (VA), Indian Health Service (IHS), 

Department of Defense (DoD)

 Israeli and Canadian data, Global Advisory Committee on Vaccine Safety

 Special evaluations underway; myocarditis case follow-up

1https://www.fda.gov/vaccines-blood-biologics/safety-availability-biologics/cber-biologics-effectiveness-and-safety-best-system 3
VaST activities

Dec 12 

Pfizer

(16+)

Feb 28 

Janssen 

(18+)

Apr 14 

CVST 

following 

Janssen

Dec 19 

Moderna

(18+)

Apr 23 

TTS updates; 

Janssen resumed

December 21, 2020 – present

41 independent meetings to review vaccine safety data

11 joint meetings with COVID-19 Vaccines Work Group focused on safety

Jan 27

Anaphylaxis 

following 

mRNA 

vaccination

Mar 1

Anaphylaxis 

updates;

Pregnancy 

vaccine safety 

data

ACIP 

votes

VaST 

assessments 

at ACIP 

meetings or 

website

CVST, cerebral venous sinus thrombosis; TTS, thrombosis with thrombocytopenia syndrome; GBS, Guillain-Barré syndrome 4

Dec Jan Feb March April May

May 12 

Pfizer

(12-15)

May 12

TTS 

updates

May 17 & 24

Myocarditis
VaST activities

December 21, 2020 – present (continued)

41 independent meetings to review vaccine safety data

11 joint meetings with COVID-19 Vaccines Work Group focused on safety

Jun 23

Myocarditis 

updates

ACIP 

votes

VaST 

assessments 

at ACIP 

meetings or 

website

CVST, cerebral venous sinus thrombosis; TTS, thrombosis with thrombocytopenia syndrome; GBS, Guillain-Barré syndrome 

July 22

GBS 

following

Janssen

Aug 13

Additional mRNA 

vaccine doses for 

immunocompromised

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Aug 30

Pfizer BLA 

(16+)

Aug 30

Safety 

overview

Sept 22

Pfizer 

3rd dose

Sept 22

Pfizer 

3rd dose

June July Aug Sept Oct Nov

Oct 21

Moderna

3rd dose

Janssen 

2nd dose

Oct 21

Moderna

3rd dose

Janssen 

2nd dose

Nov 19

Boosters 

(18+)

Nov 19

Boosters 

(18+)

Nov 2

Pfizer 

(5-11)
Safety data regarding COVID-19 booster dose 

vaccination reviewed by VaST 

 When VaST reviewed U.S. data for the September 22 ACIP vote on booster 

doses, data available for 3rd doses were mainly for those provided under 

recommendation for persons with immunocompromising conditions

 More booster vaccination safety data now available from 

– VAERS

– v-safe

– Israel Ministry of Health data

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Safety data: COVID-19 booster vaccination, VAERS

 25.9 million mRNA and 334,000 Janssen vaccine booster doses administered*

 Among 11,904 VAERS reports, most (≥93%) were non-serious 

 Almost half (46%) of VAERS reports were among persons aged ≥65 years

 Most frequently reported non-serious AEs were similar to AEs reported after 

earlier doses of COVID-19 vaccine

 54 preliminary reports of myocarditis – all after mRNA vaccination 

– 12 verified reports that met CDC case definition; 38 pending investigation 

– Age distribution reflects booster dose recommendations

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* Among reports of persons known to be 18+ years of age, who received dose 3 of Pfizer-BioNTech vaccine during Sept 22 through Nov 

15, 2021, dose 3 of Moderna vaccine during Oct 20 through Nov 15, 2021, or dose 2 Janssen during Oct 20 through Nov 15, 2021; 

received as of Nov 15, 2021.
Safety data: COVID-19 booster vaccination, v-safe

 Safety data after booster doses recorded by 725,917 v-safe participants*

– Most reported a primary mRNA vaccine series followed by booster from the 

same manufacturer

 For Pfizer-BioNTech and Moderna vaccination, local and systemic reactions 

and health impacts were reported less frequently following a booster dose 

than following dose 2 of the primary series

 Moderna booster appears to be more reactogenic than Pfizer-BioNTech 

booster, regardless of the type mRNA vaccine given previously

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*Data as of Nov 14, 2021. Includes participants who completed at least one survey in the first week after booster dose 

(administered beginning Sept 22, 2021, for Pfizer-BioNTech and Oct 20, 2021, for Moderna and Janssen). 
Safety data: 3rd dose Pfizer-BioNTech COVID-19 

vaccination, Israel Ministry of Health*

 In Israel, booster doses of Pfizer-BioNTech vaccine were phased in, first for 

persons ≥60 years and, since the end of August 2021, everyone ≥12 years of 

age eligible for 3rd dose

 ~3.9 M 3rd doses administered to persons ≥12 years (through November 15)

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

were lower after dose 3 than after either dose 1 or 2†

 Rates of myocarditis lower than after dose 2ⱡⱡ

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*Updated from: https://www.fda.gov/media/153086/download

† Passive surveillance

ⱡⱡ Proactive surveillance
VaST assessment

COVID-19 booster vaccination safety data

 Data regarding booster doses to date are reassuring; reactogenicity and AESI are 

similar to or lower than those seen after the primary series

 Myocarditis risk after a Pfizer booster dose appears lower than after dose 2

 Limited data available to assess myocarditis risk after a Moderna booster dose

– Moderna booster dose is a lower dose (50μg) than the primary series dose (100μg) 

• Deaths reported to VAERS after a primary series or a booster dose do not 

suggest any concerning patterns and reporting rates are below background rates

• VaST will continue to: 

– Review further safety regarding booster doses as data become available

– Collaborate with global vaccine safety colleagues on key issues

– Provide updates to the ACIP Work Group and ACIP at future meetings

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VaST Members

VaST Members

Keipp Talbot (ACIP)

Robert Hopkins (NVAC)

Matt Daley

Grace Lee

Veronica McNally

Kathy Edwards

Lisa Jackson

Jennifer Nelson

Laura Riley

Robert Schechter

Patricia Whitley-Williams

CDC Co-Leads

Lauri Markowitz

Melinda Wharton

Ex Officio and Liaison Representatives 

Tatiana Beresnev (NIH)

Karen Farizo; Hui Lee Wong (FDA)

David Kim (OIDP)

Jeffrey Kelman (CMS)

Matthew Clark (IHS)

Mary Rubin (HRSA)

Fran Cunningham (VA)

Limone Collins (DoD)

Administrative Support

Jared Woo

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