U.S. public health officials claim cases of myocarditis and pericarditis following COVID vaccination are rare — but new research published online in the Journal of American Medical Association (JAMA) shows they may happen more often than reported.
Post-vaccine myocarditis and pericarditis also appear to represent two “distinct syndromes,” Dr. George Diaz, with the Providence Regional Medical Center Everett, told Medscape Cardiology.
The records, obtained from 40 hospitals in Washington, Oregon, Montana and California, showed 20 people had vaccine-related myocarditis (1.0 per 100,000) and 37 had pericarditis (1.8 per 100,000).
CDC Finds ‘Likely’ Link Between Heart Inflammation and Pfizer, Moderna COVID Vaccines.
During today’s meeting, members of a CDC advisory committee acknowledged 1,200 cases of heart inflammation in 16- to 24-year-olds, and said mRNA COVID vaccines should carry a warning statement — but physicians and other public commenters accused the CDC of exaggerating the risk to young people of COVID, and minimizing the risk of the vaccines.
The Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practices (ACIP) said Wednesday there is a “likely association” of “mild” heart inflammation in adolescents and young adults after vaccination with an mRNA COVID vaccine and a warning statement is warranted.
According to a report by the COVID-19 Vaccine Safety Technical (VaST) Work Group, the risk of myocarditis or pericarditis following vaccination with the mRNA-based shots in adolescents and young adults is notably higher after the second dose and in males.
“Clinical presentation of myocarditis cases following vaccination has been distinct, occurring most often within one week after dose two, with chest pain as the most common presentation,” said Dr. Grace Lee, co-chair of VaST.
There have been more than 1,200 cases of myocarditis or pericarditis in 16- to-24-year-olds who received an mRNA COVID vaccine, according to a series of slide presentations published Wednesday at the ACIP meeting.
Myocarditis is inflammation of the heart muscle that can lead to cardiac arrhythmia and death. According to researchers at the National Organization for Rare Disorders, myocarditis can result from infections, but “more commonly the myocarditis is a result of the body’s immune reaction to the initial heart damage.”
According to the CDC, men under 30 make up the bulk of the cases and most cases appeared to be mild. Of the 295 people who developed the condition and have been discharged, 79% have fully recovered, according to the presentation. Nine people were hospitalized, with two in intensive care as of June 11, according to the CDC.
The agency said through June 11 there have been 267 cases of myocarditis or pericarditis reported after receiving one dose of the mRNA vaccines and 827 reported cases after two doses. There are 132 additional cases where the number of doses received is unknown.
Dr. Tom Shimabukuro, deputy director of the CDC’s Immunization Safety Office, said in a presentation that data from one of the agency’s safety monitoring systems — Vaccine Safety Datalink (VSD) — suggests a rate of 12.6 cases per million in the three weeks after the second shot in 12- to 39-year-olds.