The CDC’s Advisory Committee on Immunization Practices is set to meet next week to discuss a potential link between heart inflammation and COVID-19 vaccines that use messenger RNA (mRNA) technology.
The meeting was planned after vaccine safety monitoring systems showed that a small portion of vaccinated people experienced a condition called myocarditis. The CDC said Thursday that the systems revealed a higher-than-expected number of cases of heart inflammation after the second dose of mRNA COVID-19 vaccines.
The agency said more than half of the cases occurred in patients between the ages of 12 and 24 who had received either Pfizer’s or Moderna’s vaccines. Most cases (nearly 80%) occurred in men, and most happened within a week of receiving the second shot.
Assessing the risk
At least 81% of the 475 people who experienced the condition had a full recovery from their symptoms. Those who experienced the condition accounted for less than 9% of doses administered overall.
“We’re still learning about the rates of myocarditis and pericarditis,” CDC safety expert Tom Shimabukuro said, according to Bloomberg News. “As we gather more information, we’ll begin to get a better idea of the post-vaccination rates and hopefully be able to get more detailed information by age group.”
The CDC said its Advisory Committee on Immunization Practices will convene next week to look at the available evidence and assess the risk of myocarditis following mRNA vaccination for COVID-19. Pfizer said it supports the CDC’s assessment.
“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,” the company said in a statement.