Josh Nathan Kazis – Barron’s
Experts at the U.S. Food and Drug Administration and the Centers for Disease Control and Prevention are looking into whether Moderna’s Covid-19 vaccine may pose a higher risk of heart inflammation in younger adults than Pfizer’s Covid-19 vaccine, according to a report out late Thursday in the Washington Post.
Concerns about cases of heart inflammation, or myocarditis, in younger people as a side effect of messenger RNA-based Covid-19 are not new, though instances are exceedingly rare. CDC officials told an advisory committee in June that there is a “likely association” between the vaccines and heart inflammation in adolescents and young adults, but that the benefits of vaccination “clearly outweigh” the risks posed by the vaccines.
What’s new, according to the Washington Post report, is Canadian data under examination by the FDA and CDC that shows a 2.5 times higher incidence of the inflammatory condition in people who received the Moderna (ticker: MRNA) vaccine than those who received the vaccine developed by Pfizer (PFE) and BioNTech (BTNX).
The condition remains very uncommon, even in younger people who received the Moderna vaccine, the Post reported.
In a statement to Barron’s, the FDA did not respond directly to the Washington Post report. “While we won’t comment on internal meetings or discussions, we can say that FDA is absolutely committed to reviewing data as it becomes available to us,” an agency spokesperson said. “We have previously communicated about myocarditis and COVID-19 vaccines and if new information changes the risk/benefit profile, we will update the public accordingly.”
The CDC did not immediately respond to a request for comment from Barron’s. The agency told the Post that its vaccine advisory committee, the Advisory Committee on Immunization Practices, is continuing to review reports of myocarditis and pericarditis, a similar condition, among people who received Covid-19 vaccines.
In a statement sent after this article was first posted, Moderna noted that its vaccine has demonstrated substantial benefit for patients.
“Moderna is aware of the very rare occurrence of myocarditis and/or pericarditis following administration of mRNA vaccines against Covid-19,” the company said. “These are typically mild cases and individuals tend to recover within a short time following standard treatment and rest.”
Moderna shares were up 1.5% on Friday. The stock is up 264.9% so far this year, and nearly 500% over the past 12 months.
Federal health officials announced earlier this week that they plan to recommend booster doses of both Pfizer and Moderna vaccines beginning in late September for individuals who received their second dose at least eight months earlier. The FDA has not authorized booster doses yet, and the CDC’s ACIP has not yet recommended them, though the chiefs of those agencies both signed onto a letter that stated that they and other officials “conclude that booster shot will be needed.”
The FDA has also not yet authorized Covid-19 vaccines for children under the age of 12. With schools beginning to open in parts of the country, the CDC is recommending masks in school settings, though some states have banned school masking mandates.
