For more information: www.cdc.gov/COVID19

ACIP COVID-19 Vaccines Work Group

Dr. Beth Bell, Work Group Chair

April 14, 2021
Overview

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 Review of adenovirus vector COVID-19 vaccines

 Descriptions of rare clotting events seen after adenoviral vector vaccines: 

–

–

Events after AstraZeneca vaccine in Europe

Events after Janssen vaccine in US 

 ACIP Response

 Today’s Agenda
Adenovirus vector vaccines

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 Concerns for rare clotting events seen after COVID-19 adenovirus vector vaccines

 Clinical syndromes after both vaccines appear similar 

 However, extent to which the cases seen after both adenovirus vector vaccines 

represent the same syndrome is unknown

Adenovirus Vector

Janssen/J&J

AstraZeneca

Janssen

One dose

Human Adenovirus 26 vector

EUA in the US issued Feb 2021

EMA authorized for Europe

Doses not yet delivered/administered 

AstraZeneca

Two doses 

Chimp adenovirus vector 

Awaiting EUA application in the US

Approved in UK, Europe

EUA: Emergency Use Authorization; EMA: European Medicines Agency 
 Last week, EMA’s safety committee (PRAC) released report concluding:

– Strong association and probable causal link between the AZ vaccine and rare clotting events

From the European Union:

 62 cases of CVST & 24 cases of splanchnic vein thrombosis with thrombocytopenia; 18 were fatal

 Most in females <60 years of age

 Within 2 weeks of AZ vaccine receipt

 Due to different ways vaccine used in each country, cannot exclude age/gender as risk factors

From the United Kingdom:

 79 cases of thrombosis + thrombocytopenia; 19 were fatal

 44 cases of CVST (14 fatalities) & 35 cases of other clots (5 fatalities)

 51 cases were female; 28 were male

 20.2 million doses given. Estimated risk ~4 per million pop. (‘slightly higher incidence’ in younger age groups)

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AstraZeneca (AZ) vaccine

https://www.ema.europa.eu/en/news/astrazenecas-covid-19-vaccine-ema-finds-possible-link-very-rare-cases-unusual-blood-clots-low-blood

https://www.gov.uk/government/publications/use-of-the-astrazeneca-covid-19-vaccine-jcvi-statement/jcvi-statement-on-use-of-the-astrazeneca-covid-19-vaccine-7-april-2021

CVST: Cerebral Venous Sinus Thrombosis 
Reports of low platelets (thrombocytopenia) and blood clots (thrombosis) after AZ vaccine in Europe

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Vaccine-induced immune thrombotic thrombocytopenia

Two publications describing 

cases of thrombotic 

thrombocytopenia from 

Germany & Austria, and 

Norway 

Many cases had platelet 

activating antibodies 

directed against platelet 

factor 4 (PF4)

Authors propose syndrome 

entitled “Vaccine-induced 

immune thrombotic 

thrombocytopenia” (VITT) 

https://www.nejm.org/doi/full/10.1056/NEJMoa2104882?query=featured_home https://www.nejm.org/doi/full/10.1056/NEJMoa2104840?query=featured_home
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Cerebral Venous Sinus Thrombosis (CVST) –

a brief background

http://www.med.umich.edu%2F1libr%2FStroke%2FSinusVeinThromb

osis.pdf&usg=AOvVaw3qjvm4UOFcHN-eR4O3Kyf8

 Thrombosis within large vessels draining 

blood from the brain

 Mostly among people 20–50 years of age; 

female

 Risks: pregnancy, usual coagulation risks 

(e.g., oral contraceptives)

 Symptoms typically include headache, 

nausea, vomiting, other neurologic 

symptoms

– Presentation acute  weeks, months
AstraZeneca (AZ) vaccine:

Recommendations for use 

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 EMA's Pharmacovigilance Risk Assessment Committee (PRAC) does not make 

vaccine policy for the EU; each country weighs the risks and benefits of AZ 

vaccine individually

 Many countries have adopted age-based recommendations

–

–

–

UK: Adults ≥30 years of age; April 7, 2021

Australia: Adults ≥50 years of age; April 8, 2021

European countries: Adults ≥55 to ≥70 years of age

EMA: European Medicines Agency 
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Janssen/J&J COVID-19 vaccine:

Joint CDC and FDA statement on Johnson & Johnson COVID-19 vaccine, 

April 13, 2021

 As of April 12, more than 6.8 million doses of the Johnson & Johnson (Janssen) vaccine 

have been administered in the U.S. 

 CDC and FDA are reviewing data involving 6 cases of CVST in combination with low 

platelets 

 “CDC will convene a meeting of the Advisory Committee on Immunization Practices on 

Wednesday to further review these cases and assess their potential significance”. 

 “Until that process is complete, we are recommending a pause in the use of this 

vaccine out of an abundance of caution.” 

https://www.cdc.gov/media/releases/2021/s0413-JJ-vaccine.html
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Janssen/J&J COVID-19 vaccine: 

HAN released April 13, 2021

HAN Archive - 00442 | Health Alert Network (HAN) (cdc.gov)

 Recommendations for Clinicians: diagnosis and treatment

 Recommendations for Public Health: case reporting through VAERS

 Recommendations for the Public: clinical signs and symptoms to monitor 
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Janssen/J&J COVID-19 vaccine: 

HAN released April 13, 2021

HAN Archive - 00442 | Health Alert Network (HAN) (cdc.gov)

 Recommendations for Clinicians: diagnosis and treatment

–

–

–

–

Evaluate patients with a screening PF4 enzyme-linked immunosorbent (ELISA) assay as would be performed for 

autoimmune HIT. Consultation with a hematologist is strongly recommended.

Do not treat with heparin, unless HIT testing is negative

 Recommendations for Public Health: case reporting through VAERS

Encourage healthcare providers and the public to report all serious and life-threatening adverse events and 

deaths following receipt of COVID-19 vaccines to VAERS

 Recommendations for the Public: clinical signs and symptoms to monitor

Contact healthcare provider, or seek medical care if you develop severe headache, abdominal pain, leg pain, or 

shortness of breath within three weeks after vaccination with the J&J COVID-19 vaccine
 Monday 4/12: Vaccine Safety Technical Group (VaST) meeting

 Tuesday 4/13: ACIP COVID-19 vaccines Work Group meeting

 Wednesday 4/14: Emergency ACIP meeting 

 Consider implications of reported cases of thrombosis and 

thrombocytopenia after Janssen/J&J vaccine on vaccination policy

Janssen/J&J COVID-19 vaccine: 

ACIP Response 

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Purpose of Emergency ACIP meeting
 Overview of safety with Janssen’s COVID-19 vaccine, Ad26.COV2.S

Dr. Aran Maree (Janssen Pharmaceuticals Companies of Johnson & Johnson)

 Cerebral Venous Sinus Thrombosis with Thrombocytopenia after COVID-19 vaccines, 

VAERS, March 2-April 12, 2021

Dr. Tom Shimabukuro (CDC)

 VaST assessment

Dr. Grace Lee (ACIP, VaST Co-chair)

 Work Group interpretation 

Dr. Sara Oliver (CDC)

 Public Comment

 Discussion 

 VOTE: 

Janssen COVID-19 vaccine: Updated interim recommendations for use

Today's Agenda

Wednesday, April 14
ACIP members

 Beth Bell (chair)

 Matthew Daley

 Grace Lee

 Jose Romero

 Keipp Talbot

Ex-officio/government members

 FDA: Doran Fink, Rachel Zhang

 NIH: Chris Roberts

 IHS: Thomas Weiser, Uzo Chukwuma

 DOD: Bryan Schumacher

 CMS: Jeff Kelman

 BARDA: Christine Oshansky

 HHS: David Kim

CDC Lead

 Sara Oliver

Work group members

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3

Liaisons

 AAFP: Jonathan Temte

 AAP: Sean O’Leary

 ACOG: Denise Jamieson (primary), 

Laura Riley (alternate)

 ACP: Jason Goldman

 AGS: Ken Schmader

 AIM: Rob Shechter (primary), 

Jane Zucker (alternate)

 AMA: Sandra Fryhofer

 ANA: Kendra McMillan (primary), 

Ruth Francis (alternate)

 APhA: Michael Hogue

 ASTHO: Marcus Plescia

 CSTE: Susan Lett (primary), 

Christine Hahn (alternate)

 IDSA: Jeff Duchin (primary), 

Carol Baker (alternate)

Liaisons, cont’d

 NACCHO: Matt Zahn (primary), 

Jeff Duchin (alternate)

 NACI: Matthew Tunis 

 NFID: Bill Schaffner (primary), 

Marla Dalton (alternate)

 NMA: Oliver Brooks

 SHEA: Marci Drees

Consultants

 Ed Belongia

 Kathy Kinlaw 

 Dayna Matthew 

 Kathleen Neuzil 

 Stanley Perlman 

 Peter Szilagyi
 Amy Blain

 Doug Campos-Outcalt

 Mary Chamberland

 Thomas Clark

 Amanda Cohn

 Jean Cox-Ganser

 Jonathan Duffy

 Kathleen Dooling

 Anthony Fiore

 Mark Freedman

 Julia Gargano

 Sue Gerber

 Jack Gersten

 Susan Goldstein

 Sam Graitcer

CDC participants

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 Lisa Grohskopf

 Julie Garon

 Stephen Hadler

 Rita Helfand

 Susan Hiers

 Terri Hyde

 Cynthia Jorgensen

 Erin Kennedy

 Sarah Kidd

 Ram Koppaka

 Megan Lindley

 Nicole Lindsey

 Ruth Link-Gelles

 Jessica MacNeil

 Lauri Markowitz

 Natalie Thornburg

 Jennifer Verani

 Megan Wallace

 Annemarie Wasley

 Cindy Weinbaum

 Melinda Wharton

 Yon Yu

 Mona Marin

 Sarah Mbaeyi

 Nancy Messonnier

 Danielle Moulia

 Rebecca Morgan

 Titilope Oduyebo

 Anita Patel

 Janell Routh

 Stephanie Schrag

 Heather Scobie

 Edwin Shanley

 Tom Shimabukuro

 Heidi Soeters

 Mark Sotir

 Stephanie Thomas
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!