A man receives his third dose of the COVID19 vaccine on July 14, 2021 at Sheba Medical Center in Ramat Gan, Israel.

Amir Levy | Getty Images

A third dose of Pfizer’s Covid vaccine six months after a second vaccination restores infection protection to 95% in a real-world setting in Israel, according to data the company has submitted to the Food and Drug Administration.

While the effectiveness of the mRNA vaccine wears off over time, a booster dose has been shown to produce an immune response similar to the protection created after a second dose, Pfizer said in a 52-page presentation to the agency on Wednesday.

Pfizer said that data from the Israeli Covid vaccination program, which is giving boosters to the entire population, showed that a third vaccination “has a similar reactogenicity profile as after receiving the second baseline dose in the series and a high level of protection against Covid-19 results restores (back to.). approximately 95% protection). “Data was collected from July 1 to August 30, when the Delta variant was on the rise across the country.

The FDA released the data when the agency was pressured by the Biden government to approve booster injections for the general population as early as next week. However, agency staff declined to comment on the need for a third shot, citing the lack of verified data in a 23-page report released later on Wednesday.

Staff said they were reviewing other “potentially relevant” studies on immunity degradation from Pfizer’s vaccine, but the studies have produced mixed results and some of this data may be more reliable than others. The Israeli data come from an observational study that does not meet the same standards as a formal clinical study.

“It should be recognized that while observational studies can provide an understanding of effectiveness in practice, there are known and unknown biases that can affect their reliability. Because of these biases, some studies may be more reliable than others,” the FDA staff wrote in their analysis.

Pfizer’s report is intended to brief the FDA’s Advisory Committee on Vaccines and Related Biological Products, which will meet on Friday to review the application by Pfizer and its coronavirus vaccine partner BioNTech to approve Covid booster doses for the general public. The published documents provide a glimpse into the FDA’s views on third shots.

Based on the data, Pfizer said it “is applying for a booster dose of [the Pfizer vaccine] administered intramuscularly about 6 months after dose 2 in individuals over 16 years of age. “

The company also included data from a phase 3 study of approximately 300 people aged 19 to 55 years. One third of the participants were overweight and one third were obese, according to the documents.

Pfizer and BioNTech have requested the agency’s OK to distribute booster doses to people 16 years and older in the United States