The CDC said on Thursday that a “emergency meeting” with its experts will be held on June 18th to investigate uncommon but higher-than-expected reports of heart inflammation following doses of the mRNA-based Pfizer and Moderna COVID-19 vaccines.
At a meeting of the Food and Drug Administration’s Vaccine Advisory Committee on Thursday, the CDC revealed that it had found 475 cases of myocarditis and pericarditis in people under 30.
According to the CDC, 226 instances of myocarditis and pericarditis following the vaccinations have been identified thus far, according to the agency’s “working case definition.” Although the great majority of the patients have healed, 41 have persistent symptoms, 15 are still hospitalized, and three are in intensive care.
The reports reflect a small portion of the over 130 million Americans who have received complete vaccinations from either Pfizer or Moderna.
“It’s a bit of an apples-to-oranges comparison because, again, these are preliminary reports. Not all these will turn out to be true myocarditis or pericarditis reports,” cautioned Dr. Tom Shimabukuro, a CDC vaccine safety official.
Shimabukuro said their findings were mainly “consistent” with reports of rare occurrences of heart inflammation researched in Israel and released earlier this year by the US Department of Defense.
The new information on myocarditis and pericarditis was originally revealed in documents presented to the FDA’s independent advisory council, which will meet on Thursday to consider how regulators should handle emergency use authorizations for COVID vaccinations in the case of young children.
Pfizer revealed this week that it has settled on dosages to use in a clinical study in children as young as 6 months old and aimed to submit results by October after receiving an emergency use license for its COVID-19 vaccine in Americans as young as 12 last month. Moderna said on Thursday that it, too, has applied to the FDA for approval to provide its mRNA vaccine to adolescents.
While Pfizer has stated that trials for children as young as two years old are expected to be completed by September, FDA officials have previously stated that authorizing vaccines for these age groups could take longer — “mid to late fall” at the earliest — due to the additional follow-up data required for children after they receive the shots.
“We recognize that some adverse reactions, for example myocarditis or pericarditis as discussed earlier today, may be too infrequent to detect in a safety database of typical size for pre-licensure clinical trials,” said Dr. Doran Fink, a top official in the FDA’s vaccine office.
Following the second dosage, the CDC discovered that cardiac inflammation was predominantly diagnosed in younger males and adolescent boys, with “higher number of observed than expected” instances among 16- to 24-year-olds. The CDC recommended that clinicians “ask about prior COVID-19 vaccination” in individuals with heart inflammation symptoms last month.
“Risk-benefit considerations to determine whether to issue an emergency use authorization for use of a COVID-19 vaccine into healthy pediatric individuals will need to account for this information, and risk-benefit consideration will likely be different, not only compared to those for adults, but also they may be different for younger versus older pediatric groups,” Dr. Marion Gruber, director of the FDA’s vaccine office, said at the meeting.