The U.S. Food and Drug Administration (FDA) has changed the end date for a key study on post-vaccination heart inflammation without notifying the public.
But after the deadline passed, the FDA quietly changed the date.
Under a list of postmarketing requirements for the Pfizer-BioNTech vaccine, the FDA now says the same study has an "original projected completion date" of June 30, 2023.
The current status of the study is listed as "pending."
The FDA and Pfizer did not respond to requests for comment.
Jessica Adams, a former regulatory review officer at the FDA, said the wording amounts to misinformation.
"By definition, 'original' dates can't change," she wrote on Twitter, tagging the agency. "Please correct this 'misinformation.'"
Dr. Vinay Prasad, who has increasingly criticized the FDA over its decisions during the pandemic, said the new timeline "is so slow it will be entirely moot."
StudyThe study is one of nine Pfizer was to complete to examine post-vaccination adverse events.
The study is designed to "prospectively assess the incidence of subclinical myocarditis" after receipt of a third dose, or a booster, in people aged 16 to 30.
Pfizer submitted a timetable to the FDA stating the company would submit a final protocol by Nov. 30, 2021, and complete the study by June 30, 2022, according to the FDA's approval letter for the company's vaccine. The final report was due to the FDA by the end of 2022.
The study was one of several examining myocarditis and pericarditis, a related condition. Both are caused by the Pfizer and Moderna vaccines, according to U.S. officials and other experts.
Some of the vaccine-caused myocarditis cases have led to death.
Signal for Myocarditis After New BoosterThe bivalent Pfizer vaccine triggered a safety signal for adults aged 18 to 35, Richard Forshee, an FDA official, told the agency's vaccine advisory committee on Jan. 26.
Regulators cleared that bivalent and one from Moderna in the fall of 2022 despite there being no clinical data for either shot.
The adverse event happened at a concerning rate after a Pfizer bivalent in recent months, according to analyses of data from the FDA's Biologics Effectiveness and Safety initiative, which pulls from systems such as one managed by CVS Health.
"The only signal we have detected so far is for myocarditis/pericarditis following the Pfizer bivalent vaccine among adults 18 to 35 years old," Forshee told the panel.
Safety signals indicate a vaccine may cause events but don't establish causality. But officials have stressed that the bivalents are similar to the original vaccines in defending the authorization without clinical data, and have acknowledged a causal link between the original messenger RNA vaccines and the heart inflammation.
Dr. Nicola Klein, a Kaiser Permanente researcher who helps the CDC monitor vaccine safety, said that the signal for stroke wasn't as strong as that for myocarditis.
Panel Notified of CDC AnalysesDuring the public comment portion of the meeting, any panel members watching were notified that the CDC's analyses of reports to a different surveillance system concluded hundreds of adverse events met the safety signal threshold, including approximately 500 with a signal larger than that for myocarditis.
The CDC also detected more than a dozen stroke signals.
Nicole G., a member of the public who presented the data, said that the committee members should demand to know why U.S. officials "hid these safety signals."
The results were not discussed during the meeting outside of the public portion.
Before the vaccines were rolled out, CDC officials said that approximately 90 percent of signals turn out, after assessment, not to be a true signal.