The agency said observational studies don’t unanimously support the suggestion that the shot’s efficacy declines over time.
The Food and Drug Administration refrained from endorsing a Covid-19 booster shot from Pfizer and BioNTech in an analysis posted Wednesday ahead of a crucial advisory committee meeting. The agency appeared skeptical about the companies’ assertion that an apparent drop in immune protection conferred by their Covid-19 vaccine is likely due to the passage of time, rather than the emergence of the hyper-contagious Delta variant. Documents released ahead of the FDA vaccine advisory committee meeting Friday, which will focus on Pfizer’s booster application, show the companies made their conclusion based on study data and real-world evidence. The latter includes Israel’s experience observing waning immunity within its population. The country has fully vaccinated the majority of its population — largely with the Pfizer shot — and began administering boosters in July to people over 60. It has since expanded eligibility to people over 30. But FDA said observational studies don’t unanimously support the suggestion that the shot’s efficacy declines over time, while data overall show that all three vaccines authorized or licensed in the U.S. — from Pfizer-BioNTech, Moderna and Johnson & Johnson — still protect against severe disease and death. « There are many potentially relevant studies, but FDA has not independently reviewed or verified the underlying data or their conclusions, » the agency said, adding that some of those studies — including data from Israel — would be discussed Friday.
