cdc.gov/coronavirus

Adverse events among children ages 5–11 

years after COVID-19 vaccination: updates 

from v-safe and the Vaccine Adverse Event 

Reporting System (VAERS)

Dec 13, 2021

John R. Su, MD, PhD, MPH

Vaccine Safety Team

CDC COVID-19 Vaccine Task Force

1
Data from v-safe

2
Active safety monitoring for COVID-19 vaccines

v-safe is a voluntary, CDC smart phone-based monitoring program for 

COVID-19 vaccine safety in the U.S.

• Uses text messaging and web surveys to check in with vaccine recipients after 

vaccination

• Can register at any time: after first or subsequent doses

• Solicits participants' reports on how they feel after COVID-19 vaccination

• Local injection site reactions (i.e., pain, redness, swelling)

• Systemic reactions (i.e., fatigue, headache, joint pain)

• Health impacts (unable to perform normal daily activities, missed school 

or work, or received care) 

3
4

1. Text message check-ins from CDC (daily 1st week; 

weekly thru 6 weeks; then 3, 6, and 12 mo.)

Vaccine recipient completes web survey

Call center

2. Clinically 

important 

event(s) 

reported

Vaccine recipient 

3. A VAERS customer service representative 

conducts active telephone follow-up on a 

medically attended health impact event and This Photo by Unknown Author is licensed under CC BY-SA takes a report if appropriate

This Photo by Unknown Author is licensed under CC BY-SA

 Received 

medical care
Demographic summary of 41,232 v-safe participants ages 

5–11 years (as of Dec 12, 2021)*

* Includes participants who completed at least one survey in the first week after dose 1, data collected during November 3-December 12, 2021

Abbreviations: AI/AN = American Indian/Alaska Native; NHPI = Native Hawaiian or other Pacific Islander; AA=African American.

Characteristic % of participants

Sex

Female 49.7

Male 50.0

Unknown 0.4

Characteristic % of participants

Ethnicity

Hispanic or Latino 12.8

Not Hispanic/ Latino 84.1

Unknown 3.1

Race

AI/AN 0.5

Asian 6.9

Black or AA 4.5

NHPI 0.3

White 74.6

Multiracial 8.1

Other 2.7

Unknown 2.4

5

 Doses of Pfizer-BioNTech vaccine 

administered = 7,141,428 (as of Dec 9, 2021)

• Dose 1 in v-safe: 41,232

• Dose 2 in v-safe: 23,583
Reactions and health impact events reported by children ages 5–11 years 

at least once 0–7 days after Pfizer-BioNTech vaccine, by dose (as of Dec 12, 2021)

6

0

10

20

30

40

50

60

70

80

90

100

Any injection site

reaction

Any systemic

reaction

Any health

impact

Unable to

perform daily

activities

Unable to attend

school

Needed medical

care

Percentage

Dose 1

Dose 2

* Questions asked separately on questionnaire, specifying “select all that apply”

Includes 41,232 participants who completed at least one survey in the first week after dose 1, data collected during November 3-December 12, 2021
Any systemic reaction reported by children ages 5–11 years at least once 

0–7 days after Pfizer-BioNTech vaccine, by dose and days since vaccination 

(as of Dec 12, 2021)

7

0

10

20

30

40

50

60

70

80

90

100

0 1 2 3 4 5 6 7

Percentage

Days since vaccination

Dose 1

Dose 2

Includes 41,232 participants who completed at least one survey in the first week after dose 1, data collected during November 3-December 12, 2021
Top 5 solicited reactions reported by children ages 5–11 years at least once 

0–7 days Pfizer-BioNTech vaccine, by dose and severity* (as of Dec 12, 2021)

8

0

10

20

30

40

50

60

70

80

90

100

D1 D2 D1 D2 D1 D2 D1 D2 D1 D2

Pain Fever Fatigue Headache Myalgia

Percentage

Severe

Moderate

Mild

Includes 41,232 participants who completed at least one survey in the first week after dose 1, data collected during November 3-December 12, 2021

* Mild = noticeable, not problematic; moderate = limits normal daily activity; severe = daily activities difficult or impossible. Severity of fever was determined 

by temperature: mild = 38.0–38.4 C; moderate = 38.5–38.9 C; severe = 40.0+ C.
Limitations of early safety monitoring in v-safe for children 

5–11 years of age

 v-safe population likely not representative of the vaccinated U.S. 

population (e.g., selected population, reporting bias)

 At this time, data are limited to describe reactions following the second 

dose of Pfizer-BioNTech vaccine

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Summary

 Most reported reactions were 

• Mild to moderate in severity

• Most frequently reported the day after vaccination

• Slightly more frequently reported after dose 2

• Transient in nature 

 For both dose 1 and dose 2:

• Missing school was infrequently reported

• Few (approximately 1%) reported seeking medical care 

 Local and systemic reactions were reported with similar frequency as during 

clinical trials

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Data from VAERS

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+ co-managed by

CDC and FDA

Vaccine Adverse Event 

Reporting System

http://vaers.hhs.gov

VAERS is the nation’s early warning system for vaccine safety

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U.S. reports to VAERS among children ages 5–11 years after 

COVID-19 vaccination (N=3,233 reports) (as of Dec 10, 2021) 

 Doses administered = 

7,141,428 (as of Dec 9, 2021)

• Dose 1 = 5,126,642 doses

• Dose 2 = 2,014,786 doses

 Median age = 9 years

 Sex:

• Male = 1,552 (48%)

• Female = 1,587 (49%)

• Unreported = 94 (3%)

176 175 199 231 231 252

323

164 171

201

203 236

281

296

0

100

200

300

400

500

600

700

5 6 7 8 9 10 11

Reports of adverse events to VAERS

Age of reported child, years

Female Male Unreported

Median age = 9 years

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Reports among children ages 5–11 

years after COVID-19 vaccination, 

by race and ethnicity* 

(as of Dec 10, 2021) 

Race and ethnicity Reports (%)

Non-Hispanic White 1,204 (37)

Unknown or not reported 1,060 (33)

Hispanic* 399 (12)

Non-Hispanic other 187 (6)

Non-Hispanic Black 151 (5)

Non-Hispanic Asian 138 (4)

Non-Hispanic multiracial 71 (2)

Non-Hispanic American 

Indian/Alaskan Native 17 (1)

Non-Hispanic Native Hawaiian or 

Other Pacific Islander Not reported**

Total 3,233

 Most children were of White, 

non-Hispanic race and 

ethnicity, or unknown race or 

ethnicity

* Includes persons reported as of Hispanic ethnicity, but of 

unreported or unknown race

** < 10 reports

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Time from COVID-19 vaccination to symptom onset in children ages 5–11 

years (N=3,233 reports) (as of Dec 10, 2021) 

 Median time to symptom 

onset = 0 days (i.e., day of 

vaccination) (interquartile 

range = 0–1 days)

2362

418

129

82 51 28 20 20

0

500

1000

1500

2000

2500

0 1 2 3 4 5 6 7

Reports of adverse events to VAERS

Time to symptom onset, days

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Most frequent adverse events among non-serious reports to VAERS following 

COVID-19 vaccination, children ages 5–11 years (n=3,152) (as of Dec 10, 2021)

Rank Adverse event (not mutually exclusive)* n (%)

1 Incorrect dose administered 581 (18)

2 No adverse event 573 (18)

3 Product preparation issue 386 (12)

4 Vomiting 269 (9)

5 Fever 235 (7)

6 Syncope 219 (7)

7 Dizziness 205 (6)

8 Headache 204 (6)

9 Fatigue 175 (6)

10 Product administered to patient of inappropriate age 165 (5)

* Reported adverse events reflect vaccination errors and symptoms observed during preauthorization clinical trials

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Most frequent adverse events among serious reports to VAERS following 

COVID-19 vaccination, children ages 5–11 years (n=81) (as of Dec 10, 2021)

Rank Adverse event (not mutually exclusive) n (%)

1 Fever 21 (26)

2 Vomiting 17 (21)

3 Chest pain 11 (14)

4 C-reactive protein increased 10 (12)

5 Echocardiogram normal 10 (12)

6 Troponin increased 10 (12)

7 Intensive care 8 (10)

8 Respiratory viral panel 8 (10)

9 Seizure* 8 (10)

10 Blood test 7 (9)

* Upon review, seizure reports include: assessed as syncope (1), febrile seizure (1), history of seizures 

(2), potential seizure disorder (1); new onset seizure (3) 17
Two reported deaths (both still under review)

 Female, age 5 years with complicated medical history:

• Twin-to-twin transfusion, spastic cerebral palsy, seizure disorder; continuous positive air 

pressure (CPAP) at night

• Admitted to PICU for respiratory failure from rhinovirus and Mycoplasma infection; stabilized. 

Observed overnight day of vaccination, discharged home. At baseline when put to bed two 

nights later. In the morning, found pulseless and not breathing. Unable to resuscitate. 

 Female, age 6 years with complicated medical history:

• Hypoxic encephalopathy, spastic cerebral palsy, dysautonomia, neurogenic bladder, frequent 

urinary tract infections

• Ten days after vaccination, developed fever and lactic acidosis; progressive weakness, flaccid 

paralysis and loss of gag reflex; ultimately, experienced respiratory failure and hypotension; 

subsequently died; autopsy unrevealing

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Reports of myocarditis to VAERS among children ages 

5–11 years (n=10) (as of Dec 10, 2021)

 Doses administered = 7,141,428 (as of Dec 9, 2021)

 3,233 reports to VAERS among children ages 5–11 years

• 14 reports of myocarditis

• 5 reports; follow up in progress

• 9 reports with follow up information obtained

• 8 reports met CDC working case definition for myocarditis

• 4 male, 4 female

• After dose 1 = 2 cases; after dose 2 = 6 cases

• 1 report under review

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Verified reports of myocarditis among children ages 5–11 years (n=8), 

continued (as of Dec 10, 2021)

 In 6 reports with known outcomes, 5 children recovered from symptoms 

Patient Age* Sex Onset* Dose Clinical course

1 6 Male 3 2 Chest pain; elevated troponins (277 ng/L)

2 7 Female 2 2 Chest pain, elevated troponins (5.11 ng/mL); normal EKG and echo; still recovering at time 

of report

3 8 Female 2 2

Chest pain; elevated troponins (15.0 ng/mL); EKG with ST elevations, echo with mitral 

regurgitation; improved with treatment (steroids, IVIG); symptoms resolved; discharged 

home

4 9 Male 3 2 Chest pain; elevated troponins (280 ng/L); normal echo and EKG. Symptoms resolved;

discharged home. 

5 10 Female 4 1 Chest pain, shortness of breath; elevated troponins (2.6 ng/mL), normal echo and EKG. 

Symptoms resolved; discharged.

6 10 Male 0 2 Chest pain, vomiting; elevated troponins (12.9 ng/mL); symptoms resolved at time of 

report

7 10 Male 3 2 Diffuse ST elevation on EKG; elevated troponin (value not provided); additional 

information pending.

8 11 Female 12** 1 Pleuritic chest pain and difficulty breathing; elevated troponins (5.3 ng/mL), EKG with 

nonspecific ST and T wave changes, normal echo. Symptoms resolved; discharged home.

* Age listed in years, time to symptom onset listed in days

** History of headache and gastrointestinal symptoms (vomiting, diarrhea) 3 or 4 days before chest pain began; potential viral syndrome. 20
Data from VSD

21
22

VSD

Vaccine

Safety

Datalink

 9 participating integrated healthcare organizations

 Data on over 12 million persons per year
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birth and death 

certificate 

information & 

family linkage

immunization 

enrollment and records

demographics

Types of information in VSD

linked by 

study IDs

Images created by Wilson Joseph, Megan Mitchell, Ananth, and Iga from the noun project

outpatient and 

clinic visits

emergency room 

visits

procedure codes hospital discharge 

diagnosis codes

charts and 

electronic 

health records
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VSD COVID-19 vaccine prespecified 

surveillance outcomes Settings Risk window

(days)

Acute disseminated encephalomyelitis E, I 1-21, 1-42

Acute myocardial infarction – First Ever E, I 1-21, 1-42

Acute respiratory distress syndrome* E, I 0-84

Anaphylaxis – First in 7 days* E, I 0-1

Appendicitis E, I 1-21, 1-42

Bell’s palsy – First Ever E, I, O 1-21, 1-42

Cerebral venous sinus thrombosis E, I 1-21, 1-42

Disseminated intravascular coagulation E, I 1-21, 1-42

Encephalitis / myelitis / encephalomyelitis E, I 1-21, 1-42

Guillain-Barré syndrome E, I 1-21, 1-42

Immune thrombocytopenia E, I, O 1-21, 1-42

Kawasaki disease E, I 1-21, 1-42

Multisystem inflammatory syndrome in children/adults* E, I 0-84

Myocarditis / pericarditis – First in 60 Days E, I 1-21, 1-42

Narcolepsy / cataplexy* E, I, O 0-84

Pulmonary embolism – First Ever E, I 1-21, 1-42

Seizures E, I 1-21, 1-42

Stroke, hemorrhagic E, I 1-21, 1-42

Stroke, ischemic E, I 1-21, 1-42

Thrombosis with thrombocytopenia syndrome – First Ever E, I 1-21, 1-42

Thrombotic thrombocytopenic purpura E, I 1-21, 1-42

Transverse myelitis E, I 1-21, 1-42

Venous thromboembolism – First Ever E, I, O 1-21, 1-42

Abbreviations: E=ED, I=Inpatient, O=Outpatient; *Descriptive monitoring 

 Near real-time sequential (i.e., 

weekly) monitoring (rapid 

cycle analysis) as data become 

available 

 As of Dec 14, 2021

 333,000 doses administered 

(226,000 dose 1, 107,000 dose 2)

 No confirmed reports of 

myocarditis in 0–7; 0–21-day risk 

windows)
Summary

 During November 2 – December 10, 2021, VAERS received 3,233 

reports among children ages 5–11 years 

• As of December 9, 7,141,428 doses of pediatric Pfizer-BioNTech vaccine 

administered

• Median age = 9 years; sex distribution by age comparable

• Most reports among non-Hispanic White children, or children without race or 

ethnicity reported

• Median time to symptom onset = 0 days (day of vaccination)

• Majority of reports (97%) non-serious

• Two reported deaths in children with complicated medical histories

• 8 reports meeting myocarditis case definition; clinical course mild

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Summary (continued)

• Most common adverse events = vaccination errors and symptoms observed in 

preauthorization clinical trials

• Reported race and ethnicity in v-safe and VAERS comparable

• In v-safe, 

• Reactions following dose 2 were slightly more frequent

• Most reactions were mild to moderate and transient 

• Regardless of dose, ≤10% reported missing school

• Few (approximately 1%) reported seeking medical care

• No reports of myocarditis in 0–7, 0–21-day risk windows in VSD

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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!

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