Fact Check-Graph showing increase in myo/pericarditis after COVID-19 vaccine rollout does not confirm link

A visual showing reports of myocarditis and pericarditis increasing in the United States in tandem with the country’s COVID-19 vaccine rollout has gone viral online – and has been posted alongside claims that the conditions are linked to vaccines. The Centers for Disease Control and Prevention (CDC) is investigating the cases but says a relationship to the vaccines has not been confirmed.

Social media users have shared a red bar chart showing total yearly reports to the U.S. Vaccine Adverse Event Reporting System (VAERS) of myocarditis, an inflammation of the heart muscle, and pericarditis, an inflammation of the heart’s sac. (here, here, here, here).

The data includes reports after all vaccines from the years 2010 to 2021 and appears to show more than 11,000 reports for 2021 alone, compared to very low numbers in previous years.

Captioning the bar chart in a post, one social media user wrote (here “How strange is it ?? ... heart problems increased after vaccinations .... DID YOU NOTICE OR YET ?? !!!”

However, there have not been this many reports of myocarditis and pericarditis to VAERS after COVID-19 vaccination, according to the CDC and Reuters analysis of the database. The claim that cases have risen drastically after COVID-19 vaccination also misses context.

VAERS, managed by the CDC and U.S. Food and Drug Administration (FDA), documents suspected reactions to COVID-19 vaccines to detect possible safety issues.

It is true that since 1990 most of the myocarditis and pericarditis reports to VAERS were made after the U.S. COVID-19 vaccination program began, a CDC spokesperson told Reuters.

However, there have been far fewer than 11,000 reported for 2021 so far.

The graph, originally published on website OpenVAERS (here), shows reports of the conditions after all available vaccines.

OpenVAERS has yet to respond to a Reuters request to detail their search methodology but a Reuters analysis of VAERS entries for “myocarditis” and “pericarditis” found fewer than 3,500 instances.

The CDC confirmed to Reuters a total of 2,337 reports of myocarditis in VAERS for all vaccines from 1990 to Nov. 11, 2021.

Of those, 1,969 myocarditis or pericarditis reports concerned people aged 30 and younger who received COVID-19 vaccines.

The CDC and FDA investigated the reports and, through interviews with medical providers and medical record reviews, confirmed 1,005 cases met the criteria for myocarditis, pericarditis, or myopericarditis. The CDC’s case definitions can be found here (page 978, Table 1).

Most cases were reported after vaccination with mRNA COVID-19 vaccines Pfizer-BioNTech or Moderna, particularly in male adolescents and young adults.

However, a link to the vaccines has not been confirmed.

The organisations are investigating the reports and conducting longer-term monitoring to determine whether there is a relationship to COVID-19 vaccination, the CDC said.

No deaths have been conclusively linked to the conditions following mRNA COVID-19 vaccination, they added.

The CDC also pointed Reuters to data presented during its most recent Advisory Committee on Immunization Practices meeting (here), indicating most of those affected made a full recovery within three months.

Patients with myocarditis or pericarditis after mRNA COVID-19 vaccination have “responded well to conservative treatment and outcomes have been favorable,” the spokesperson said.

COVID-19 infection is associated with a 16-fold increase in risk of myocarditis compared to individuals without the virus, although the overall risk is low, U.S. hospital data shows (here).

According to quantitative benefit-risk analysis of COVID=19 vaccines in 5- to 11-year-olds, the FDA found the numbers of “clinically significant COVID-19-related outcomes

prevented would clearly outweigh the numbers of vaccine-associated excess myocarditis cases” (here).


Misleading. There were 2,320 total reports of myocarditis in VAERS from 1990 to Oct. 27, 2021, according to the CDC. Reports of myocarditis and pericarditis have increased since the rollout of COVID-19 vaccines, with 1,005 cases confirmed, but a link to the shots has so far not been established.

This article was produced by the Reuters Fact Check team. Read more about our fact-checking work here.