But the FDA said observational studies did not unanimously support the suggestion that the vaccine’s effectiveness declines over time, while data overall shows that all three vaccines licensed or licensed in the United States – from Pfizer-BioNTech, Moderna and Johnson & Johnson – still protect against serious illness and death.
“There are many potentially relevant studies, but the 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 on Friday.
Israeli data, some of which is expected to be released on Wednesday, shaped the Biden administration’s efforts to start giving boosters to most adults next week. In his absence, federal scientists and other public health experts questioned the move towards recalls when available data shows vaccines still offer high protection against serious illness, hospitalization and death in most age groups.
“Known and unknown biases” can affect the reliability of observational studies, the FDA warned.
“In addition, studies conducted in the United States on the post-authorization efficacy of [the Pfizer-BioNTech vaccine] may most accurately represent the effectiveness of the vaccine in the US population, ”the agency said.
Still, the FDA acknowledged that the companies met predefined criteria for success in their recall study.
The third dose of the vaccine was “well tolerated” among study participants, Pfizer said, with no serious adverse events or deaths reported. Mild to moderate pain at the injection site, fatigue, chills, and muscle stiffness have been commonly reported.
Pfizer’s recall request would apply to persons 16 years of age and over. If members of the FDA’s vaccine advisory committee vote to recommend recalls, the FDA and the CDC’s own external advisory group could act within days to clear the Pfizer booster for use. The FDA is not bound by the recommendations of its advisory committees, but often follows them.
The Biden administration’s goal of deploying boosters by September 20 has sparked controversy within the FDA. Two of the agency’s top vaccine scientists, Marion Gruber and Philip Krause, recently decided to retire this fall – in part because of frustration over the planned recall launch.
Gruber, director of the FDA’s Office of Vaccines Research and Review, will make a presentation Friday at the FDA advisory committee meeting.
Learn more about side effects: About 5% of the study subjects – mostly women – had swollen lymph nodes within four days of the injection, Pfizer said. All cases except one, a known side effect of the vaccine, were considered mild.
“As dose 3 is a booster, it is not surprising that stimulation of a lymph node reaction by vaccination is present as part of a significant increase in neutralizing antibodies observed after dose 3,” said Pfizer.
No participant suffered from myocarditis or pericarditis, two inflammatory heart conditions related to the vaccine, especially in men 30 years of age and under.
Pfizer also recommends that its booster dose be given six months after a patient’s second of two initial doses, rather than the eight months suggested by senior health officials in the Biden administration. The final decision on the timing will rest with federal regulators at the FDA and CDC.
And after: The FDA will publish the issues that the advisory committee will consider at its Friday meeting on Wednesday. In addition to Pfizer and BioNTech’s recall app, the agency is considering a Moderna recall app.