Pfizer and BioNTech submitted an application to the US Food and Drug Administration for emergency use authorization of an additional booster dose of their Covid-19 vaccine for adults 65 and older who have gotten a booster dose of any of the authorized or approved vaccine, the companies said Tuesday. The submission is based on two data sets from Israel. “Both data sets showed evidence that an additional mRNA booster increases immunogenicity and lowers rates of confirmed infections and severe illness,” the companies said in a news release. The first data set cited in the release was an analysis of records for more than 1.1 million adults 60 and older by the Israeli Ministry of Health that showed a decreased rate of infection and severe illness after a second booster. The participants had no known history of Covid-19 and were eligible for an additional booster. “These data showed rates of confirmed infections were 2 times lower and rates of severe illness were 4 times lower among individuals who received an additional booster dose of the Pfizer-BioNTech COVID-19 Vaccine administered at least four months after an initial booster (third) dose compared to those who received only one booster dose,” the news release says. That research has not been peer-reviewed or published in a professional journal. The second data set is the result of an ongoing trial looking at health care workers 18 and older who had gotten three doses of Pfizer/BioNTech’s Covid-19 vaccine. Those findings were published Wednesday in the New England Journal of Medicine. Of 700 participants, 154 received an additional Pfizer/BioNTech booster at least four months after their third dose. The fourth dose was safe and boosted antibody levels similar to what was seen after a third dose but didn’t appear any more effective at preventing Omicron infection. The companies said this additional booster did not result in any new safety concerns. Although not included in the EUA submission, the companies referenced other “emerging evidence” that could support the need for an additional booster. “These early studies indicate that an additional booster dose of the Pfizer-BioNTech COVID-19 Vaccine administered at least 4 months after an initial booster dose could restore antibody titers to peak post-third dose titer levels, improve protection against both infection and severe disease in individuals 60 years of age and older in Israel, and have a similar safety profile to that of previous doses.” The FDA said it will review Pfizer and BioNTech’s request “as expeditiously as possible using our thorough and science-based approach.” The agency also said it will convene its independent vaccine advisers, the Vaccines and Related Biological Products Advisory Committee, in April “to have a transparent discussion about considerations for 2022 booster shots, including whether and when those boosters may be needed and for which populations, based on the available data and latest science on circulating or emerging virus variants.” A date for the meeting has not been set. Pfizer CEO Albert Bourla said Sunday that he expects that a fourth dose of Covid-19 vaccine will be needed. “It is necessary – a fourth boost for right now. The protection we are getting from the third, it is good enough – actually quite good for hospitalizations and deaths – is not that good against infections, but doesn’t last very long,” Bourla said on CBS’ “Face the Nation.” “But we are just submitting those data to the FDA, and then we’ll see what the experts also would say outside Pfizer.” A few countries area already offering fourth doses of Covid-19 vaccines. In the United States, only certain immunocompromised adults can receive three doses of the coronavirus vaccine and a fourth shot as a booster dose. Two doses of the Pfizer/BioNTech coronavirus vaccine are available for people 5 and older, and people 12 and older are eligible to receive a booster five months after their second shot.