One person receives a dose of the Pfizer-BioNTech vaccine for coronavirus disease (COVID-19) at a mobile inoculation site in the Bronx, New York, on August 18, 2021.
David ‘Dee’ Delgado | Reuters
Food and Drug Administration staff on Wednesday declined to take a stand to support Pfizer’s Covid-19 vaccine booster shots, saying U.S. regulators have not yet reviewed all available data.
“There are many potentially relevant studies, but the FDA has not independently reviewed or verified the underlying data or its findings,” they wrote in a 23-page document posted on the agency’s website. “Some of these studies, including data from the immunization program in Israel, will be summarized during the VRBPAC meeting on September 17, 2021.”
Staff said some observational studies have suggested a decrease in the effectiveness of the Pfizer vaccine over time against symptomatic infection or against the delta variant, while others have not.
“Overall, the data indicate that currently licensed or licensed COVID-19 vaccines still offer protection against serious COVID-19 disease and death in the United States,” they wrote.
Data the FDA is studying includes Israeli efficacy numbers, where researchers have published observational studies showing the effectiveness of the Pfizer vaccine against decreased infection over time.
In separate documents released Wednesday, Pfizer argued that a third dose of the Covid vaccine six months after a second shot restores 95% protection against infection.
FDA staff seemed to take a skeptical tone about the data, as the observational study does not adhere to the same standards as a formal clinical trial.
“It should be recognized that while observational studies may provide insight into real-world effectiveness, there are known and unknown biases that can affect its reliability,” agency staff said. “In addition, U.S.-based studies on the post-authorization efficacy of BNT162b2 may more accurately represent the efficacy of the vaccine in the U.S. population.”
The staff report is intended to inform the FDA Advisory Committee on Vaccines and Related Biological Products, which meets Friday to review Pfizer’s request to approve Covid booster doses for the general public. Published documents provide an insight into the agency’s vision of third parties.
The Biden administration has said it wants to start offering booster shots to the general public as early as next week, pending FDA approval. The move is part of President Joe Biden’s broader plan to tackle a higher number of Covid cases fueled by the rapidly spreading delta variant.
Scientists and other health experts have repeatedly criticized the plan, saying the data from cited federal health officials is unconvincing, characterizing the administration’s push by proponents as premature.
Currently, there is no consensus in the biomedical community about boosters for the general public, said Dan Barouch, an immunologist at Harvard Medical School.
“There are high-level experts who fall into different aspects of the debate,” he said. “At this point it will be interesting to see where the debate is going, but obviously it is known that the Biden administration has suggested that drivers are needed.”
The Biden administration has cited three studies, published by the Centers for Disease Control and Prevention, that showed that protection against Covid vaccines decreased in several months. The administration’s plan, outlined by senior health officials, calls for a third dose eight months after people receive the second vaccine from the Pfizer or Moderna vaccine. Biden said scientists were reviewing whether to increase the third shot three months.
A group of scientists, including two senior officials from the FDA and the World Health Organization, published an article in The Lancet magazine on Monday arguing that no reinforcement shots are needed at this time for the general public. While the effectiveness of the Covid vaccine against mild diseases may decrease over time, protection against serious diseases seems to persist, scientists said.
On Tuesday, WHO officials again called on rich nations to stop distributing booster doses of the Covid vaccine in hopes of making more shots at the poorest countries with delayed vaccination rates.
“There are countries with vaccination coverage of less than 2%, most in Africa, that do not even receive their first and second dose,” Tedros CEO Adhanom Ghebreyesus told a news conference. for reinforcers, especially healthy populations, it’s not really good. “