The theme of myocarditis and pericarditis following mRNA vaccination emerged in today’s Vaccines and Related Biological Products Advisory Committee meeting, which reviewed preliminary safety data of Pfizer-BioNTech vaccine in children aged 12 to 15. The risk, however, appears to be small.
As of May 31, there were 116 reports of myocarditis or pericarditis after the first dose of Pfizer-BioNTech vaccine. There were 100 for the first dose of Moderna vaccine. The problem, however, appears to be more common after the second dose. The government has collected 372 reports of myocarditis or pericarditis after the second dose of Pfizer-BioNTech vaccine and 201 for the Moderna vaccine.
Early data suggests a connection between the mRNA vaccines and myocarditis and pericarditis. Out of 2.3 million doses administered to 16-to-17-year-olds, the VAERS database lists 79 cases of myocarditis or pericarditis. The expected rate in a population that size would be between two and 19 cases.
A Pfizer spokesperson said that the company is aware of the reports predominantly in male adolescents and young adults. “According to the CDC, the amount of reports is small given the number of doses administered and patients have typically rapidly improved with conservative treatment,” said Keanna Ghazvini, senior associate, global media relations at Pfizer. “It is important to note that CDC continues to recommend COVID-19 vaccinations for individuals aged 12 and older.”
Pfizer notes that it expects adverse events unrelated to vaccination to occur at a “similar rate in vaccinated individuals as they would in the overall population,” Ghazvini said. “All adverse events are regularly and thoroughly reviewed by Pfizer as well as by CDC,” she continued. “It is important to understand that a careful assessment of the reports is ongoing and it has not been concluded that the mRNA COVID-19 vaccines cause myocarditis or pericarditis. Myocarditis and pericarditis are often caused by viral infections; infection with SARS-CoV-2 has been reported to cause myocarditis.”
Pfizer supports CDC’s request for “careful assessment of suspected myocarditis and pericarditis cases to further our understanding of the cases reported,” Ghazvini concluded.
One factor to keep in mind is that not all of the currently reported cases of myocarditis and pericarditis are accurate, stressed Dr. Tom Shimabukuro, the deputy director of the Immunization Safety Office at CDC. “It’s a bit of an apples-to-oranges comparison because, again, these are preliminary reports,” he said. “Not all these will turn out to be true myocarditis or pericarditis reports.”
The CDC has scheduled an emergency meeting for June 18 to discuss the reports.
CDC has followed 221 discharged patients with the conditions. Some 81% (180) had a full recovery.
Filed Under: Infectious Disease