Pfizer and BioNTech have submitted a request to the American Food and Drug Administration (FDA) to authorize a fourth booster dose of their coronavirus vaccine for people over 65 years of age.
The request is based on two data sets originating from Israel and analyzed at a time when the Omicron variant was widely circulating. Both showed evidence that an additional mRNA boost increases immunogenicity and reduces rates of confirmed infections and severe disease.
Specifically, an analysis of Israeli Ministry of Health records was conducted on more than 1.1 million adults over the age of 60 who had no known history of SARS-CoV-2 infection and who were eligible for a booster. additional (fourth dose).
These data showed that rates of confirmed infections were two times lower and rates of severe illness were four times lower among people who received an additional booster dose of the Pfizer-BioNTech COVID-19 vaccine administered for at least four months. , after the third booster dose, compared with those who received only one booster dose.
The presentation also includes the results of an ongoing, open-label, non-randomized clinical trial in healthcare professionals over 18 years of age in Israel who had been vaccinated with three doses. Among 154 (of 700) participants who received an additional (fourth) booster dose of the Pfizer-BioNTech COVID-19 vaccine, at least four months after the initial booster, neutralizing antibodies increased approximately 7- to 8-fold at two and three weeks after the fourth additional booster dose.
In addition, there was an 8-fold and 10-fold increase in the number of neutralizing antibodies against the Omicron variant (B.1.1.529) one and two weeks after the additional booster dose, respectively. The study also did not show any new safety problems in people who received an additional booster dose of the vaccine.
Also, according to the company, emerging evidence, including data from Kaiser Permanente of Southern California, suggests that the efficacy against symptomatic COVID-19 and severe disease caused by the Omicron variant declines 3 to 6 months after receiving the third initial booster dose.
These early studies indicate that an additional booster dose of Pfizer-BioNTech COVID-19 vaccine given at least 4 months after an initial booster dose could restore antibody titers to peak levels after the third dose.
