cdc.gov/coronavirus

Myocarditis Outcomes Following mRNA 

COVID-19 Vaccination

Preliminary Data: data are subject to change

Advisory Committee on Immunization Practices

February 4, 2022

Ian Kracalik PhD MPH

Vaccine Safety Team

CDC COVID-19 Vaccine Task Force
Disclaimer

 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 (CDC)

 Mention of a product or company name is for identification 

purposes only does not constitute endorsement by CDC or FDA

2
Myocarditis following mRNA COVID-19 vaccination

 Evidence from safety monitoring systems in multiple countries supports the 

finding of an increased, but still rare, risk of myocarditis following mRNA COVID19 vaccination*

• Risk:

‒ Highest in adolescents and young adults

‒ Males > females

‒ Following dose 2 > dose 1

• Onset within a few days of vaccination, mostly within a week

• Severity of cases varies; most who presented to medical care have responded 

well to medications and rest

• Assessment of myocarditis health effects after COVID-19 vaccination in 

progress* https://www.who.int/news/item/09-07-2021-gacvs-guidance-myocarditis-pericarditis-covid-19-mrna-vaccines 3
CDC enhanced surveillance for myocarditis outcomes after 

mRNA COVID-19 vaccination in Vaccine Adverse Event 

Reporting System (VAERS) case reports* 

4

 Purpose: Assess functional status and clinical outcomes among individuals 

reported to have developed myocarditis after mRNA COVID-19 vaccination

 Methods: A two-component survey conducted at least 90 days after the onset 

of myocarditis symptoms

• Patient survey: Focused on 12–29 years of age, ascertain functional status, clinical 

symptoms, quality of life, and need for medication or other medical treatment 

• Healthcare provider (e.g., cardiologist): Gather data on cardiac health and 

functional status

 Timeline: Data collection August 2021–January 2022

* https://www.cdc.gov/coronavirus/2019-ncov/vaccines/safety/myo-outcomes.html
Preliminary data from surveys of patients at least 

90 days post myocarditis diagnosis 
6

Outreach focusing on myocarditis patients 12–29 years of age

 As of November 2021, VAERS had received ~989 reports of myocarditis or 

myopericarditis after COVID-19 vaccination that met CDC case definition*

 Of these, ~850 patient ages 12–29 years had reached 90 days post-myocarditis 

diagnosis

• Of ~850 patients 90 days post diagnosis, 648 (81%) had a phone number listed

‒ Of the ~648 patients who were called, ~360 (56%) completed the survey; 

~270 (42%) were unreachable and 18 (3%) declined to participate 

‒ For the 360 patients interviewed, time from myocarditis onset to interview 

was 143 days (IQR: 131, 162)

* https://www.cdc.gov/mmwr/volumes/70/wr/mm7027e2.htm
0

20

40

60

80

100

120

M F M F M F M F

12 to 14 15 to 19 20 to 24 25 to 29

Number of patients

Sex and age group 7

Most patients diagnosed with myocarditis were young males

 Median patient age was 18 years (IQR: 15–22); 

 Of the 360 patients 90 days post myocarditis diagnosis, 86% (308) were male

17%

2%

38%

6%

21%

3%

11%

2%

Male patients

Female patients
8

Race and ethnicity of myocarditis patients (N=360) 

0 50 100 150 200 250

White,

 non-Hispanic

Hispanic

Asian,

 non-Hispanic

Black,

 non-Hispanic

Multi-racial,

 non-Hispanic

Other,

non Hispanic

American Indian orAlaskan Native,

non-Hispanic

Number of patients

62%

20%

5%

4%

4%

3%

<1%

*4 patients did not provide a response
9

 87% (314/360) received two doses of a COVID-19 vaccine

• Of those who received two doses, 98% (307/314) reported receiving 

both doses before they were diagnosed with myocarditis

• 9% (31/360) had a positive COVID-19 test before their 

myocarditis diagnosis

Prior to their myocarditis diagnosis, most patients received 

two doses of a COVID-19 vaccine
10

Self reported previous medical history among patients with 

myocarditis after mRNA COVID-19 vaccination (N=360)

 60 (17%) had any condition

• 11 (3%) had an arrhythmia

• 6 (2%) had congenital heart disease

• 6 (2%) had a history of myocarditis

• 2 (<1%) had Kawasaki disease 

• 1 (<1%) had previous heart failure

• 32 (9%) had a history of asthma

• 7 (2%) had an autoimmune disorder

• 5 (1%) genetic or chromosomal condition

• 4 (1%) were immunosuppressed 

• 1 (<1%) had a history of Leukemia

• 1 (<1%) had type 1 diabetes 
11

Most patients with myocarditis after vaccination reported being 

hospitalized at the time of myocarditis diagnosis (n=360)

 92% (324) were hospitalized

• 4% (13) were readmitted following myocarditis; 8 of 13 (62%) were 

readmitted because of a concern with the heart

• 20% (71) were prescribed medication for their heart as of their last 

appointment with the provider
12

Missed school or work within the 2 weeks prior to the date of 

the interview reported among patients with myocarditis after 

vaccination (N=360)

 46 (8%) reported missing school

• Of these, 10 (37%) believed it was due to their myocarditis

 19 (5%) missed work

• Of these, 7 (37%) believed it was due to their myocarditis
Self-reported symptoms within 2 weeks prior to the date of the 

interview among myocarditis patients (n=360)

• About half (49%) 

reported 

experiencing at 

least 1 symptom in 

the prior two 

weeks

0 50 100 150 200 250 300

no

yes

no

yes

no

yes

no

yes

Fatigue Palpitations SOB Chest pain

Number of patients 13

78%

25%

78%

22%

75%

32%

68%

22% Shortness 

of breath

Chest 

pain

Palpitations

Fatigue
14

EuroQol-5D-5L measurement of health status among patients 

who developed myocarditis after vaccination (n=242)
Preliminary data from completed cardiologist or 

other healthcare provider surveys
16

Outreach to cardiologists or other healthcare providers

 Of the 360/648 patients interviewed, ~346 (96%) listed contact information for a 

cardiologist or other healthcare provider

• Of the 346 providers with contact information listed, 229 completed a survey

• An additional 151 providers completed surveys they had submitted for multiple 

patients in VAERS or provided contact information via the VAERS report

• We were unable to contact 268 providers

• In total, 380 providers completed the survey with a median of 191 days (IQR: 

170, 216) from patient myocarditis onset to date of provider survey
17

The proportion of myocarditis patients cleared for physical 

activity by their cardiologist or healthcare provider has 

increased (n=380) 

At time of myocarditis diagnosis, 83% of patients 

had restrictions on their physical activity

83% 

Restricted

At time of provider survey, at least 90 days post 

diagnosis, only 39% had restrictions

*25 (7%) were unsure

39% 

Restricted
0

50

100

150

200

250

Same cardiac status as

at the initial

myocarditis diagnosis

Improved, but not

fully recovered

Probably fully

recovered, awaiting

additional information

Fully recovered

Number of Patients

Based on the cardiologists/healthcare provider assessment, 

most patients appear to have fully or probably recovered from 

their myocarditis (n=380) 

 81% (309) of cardiologists or healthcare providers indicated the patient was 

fully or probably recovered

Patient Recovery 66% 

15% 15% 

1% 

*8 providers were unsure 18
Proportion of myocarditis patients deemed to be fully or 

probably recovered by their healthcare provider (n=309)

19
Results of the most recent cardiac function test (n=380)

53%

36%

93%

77%

90% 89%

46%

64%

7%

23%

10% 11%

0

50

100

150

200

250

300

350

400

Troponin Cardiac MRI Echocardiogram Electrocardiogram Exercise stress test Ambulatory rhythm

monitoring

Number of patients

Normal or baseline Abnormal or elevated

20
121

68

23 18

32

2

8

1 1 6 3 8 3 5

92

53

17

9

20

0 3 0 1 4 3 5 1 4

0

20

40

60

80

100

120

Late gadolinium enhancementInflamation or edemaWall motion abnormalitiesST segment elevationT wave abnormalitiesArrhythmiaConduction delays or blocksEctopic rhythymArrhythmiaOther cardiac concernOther non-cardiac concernArrhythmiaConduction delays or blocksEctopic rhythym

Cardiac MRI Electrocardiogram Exercise stress test Ambulatory rhythym

monitoring

Number of patients

All patients

Abnormal findings from most recent cardiac function test

Patients fully or probably recovered
Overlap of abnormal findings among most recent cardiac 

function tests

Troponin 51

EKG 26 22

Ambulatory rhythm 3 2 6

Exercise stress test 1 1 1 10

ECHO 9 7 31 20 0

60–80%

40–60%

20–40%

0–20%

22
Comparison of cardiac function tests at time of diagnosis and follow-up

14

127

239

248

57

75

36

340

4

At �me of ini�al diagnosis At �me of follow-Up

68

79

233

253

17

174

110

20

186

Number of myocardi�s pa�ents

Number of myocardi�s pa�ents

elevated elevated
Comparison of cardiac function tests at time of diagnosis and follow-up

24

Number of myocarditis patients 

Number of myocarditis patients 

14

127

239

At �me of ini�al diagnosis At �me of follow-Up

68

79

233
Comparison of cardiac function tests at time of diagnosis and follow-up

25

248

57

75

253

17

110

At time of initial diagnosis At time of follow-up

Number of myocarditis patients 

Number of myocarditis patients 
Comparison of cardiac function tests at time of diagnosis and follow-up

26

At time of initial diagnosis At time of follow-up

36

340

4

174

20

186

elevated elevated

Number of myocarditis patients 

Number of myocarditis patients 
Normal/Baseline function or absence of symptoms

Abnormal function or presence of symptoms

Unknown or no test results available

Patients deemed fully or probably fully recovered

Patients deemed not recovered

27

Cardiac assessment and symptoms among patients deemed to be 

recovered and not recovered from their myocarditis
Normal/Baseline function or absence of symptoms

Abnormal function or presence of symptoms

Unknown or no test results available

Patients deemed not recovered

Cardiac assessment and symptoms among patients deemed to be 

recovered and not recovered from their myocarditis

28

Patients deemed fully or probably fully recovered
Normal/Baseline function or absence of symptoms

Abnormal function or presence of symptoms

Unknown or no test results available

Patients deemed not recovered

29

Cardiac assessment and symptoms among patients deemed to be 

recovered and not recovered from their myocarditis

Patients deemed fully or probably fully recovered
Summary

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 At least 90 days after myocarditis diagnosis, most patients reported no impact 

on their quality of life, and most did not report missing school or work

 Only 13 (4%) were readmitted to the hospital 

 Most (81%) healthcare providers indicated the patient was probably fully or 

fully recovered

 There did not appear to be a single test that was indicative of recovery

 To our knowledge, there were no vaccine-associated myocarditis deaths in this 

group

 Ongoing efforts to continue patient follow-up and contact myocarditis patients 

who were not yet recovered at time of survey 

 Surveys are being modified for children aged 5-11 and follow-up to start in 

February 2022
Acknowledgments

 VAERS Team

• VAERS TTS abstraction team

• VAERS Myopericarditis abstraction team

• VAERS data team

 Clinical Immunization Safety Assessment Project

 COVID-19 Vaccine Task Force Data Monitoring and Reporting Group

Thanks to the many people who made analysis of these data possible:

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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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