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September 17, 2021: -According to data submitted to the Food and Drug Administration, a third dose of Pfizer’s Covid vaccine six months after a second dose gives 95% protection from infection in a world set in Israel.
On Wednesday, while the effectiveness of the mRNA vaccine wanes with time, a booster dose was shown to elicit an immune response similar to the protection generated after a second dose, Pfizer said in a presentation released by the agency.
Pfizer said data from the Covid vaccination program of Israel is administering boosters to the whole population show that a third dose “has a reactogenicity profile similar to that seen after receipt of the second primary series dose and restores high levels; of protection against Covid-19 outcomes.” The data was collected from July 1 through August 30, when the delta variant surged throughout the country.
The FDA is releasing the data as the agency faces pressure from the Biden administration to authorize booster doses for the general population by next week. But agency staff declined to take a stance on the need for a third dose, citing the lack of verified data in a 23-page report released later on Wednesday.
The staff said it would review the other “potentially relevant” studies on waning immunity from Pfizer’s vaccine. Still, the studies have produced mixed results, and some of that data may be reliable than others. The Israel data came from an observational study, which does not adhere to the same standards of a formal clinical trial.
“It should be recognized that while observational studies can enable understanding of real-world effectiveness, there are known and unknown biases that will affect their reliability. Few studies may be more reliable than others,” the FDA staff wrote in their analysis due to these biases.
Pfizer’s report means to brief the FDA’s Vaccines and Related Biological Products Advisory Committee, meeting Friday to review the request by Pfizer and its Covid-19 vaccine partner, BioNTech, to approve Covid booster shots for the general public. The documents are publishing a glimpse of the FDA’s view on third doses.
Based on the data, Pfizer said it “is requesting licensure of a booster dose of administered intramuscularly approximately six months after dose 2 in individuals greater than 16 years of age.”
The company is including data from a Phase 3 trial of almost 300 people aged 19 to 55. One-third of participants were overweight, and one-third were obese, according to the documents.
Pfizer and BioNTech seek the agency’s OK to distribute booster doses to people 16 and older across the U.S.
