An Israeli study has found that a fourth dose of the Pfizer-BioNTech SARS-CoV-2 vaccine raises antibody levels, but does not prevent Omicron variant infections, the Financial Times reports.
Healthcare workers at Sheba Medical Center have been part of a study that began in December 2020 to examine antibody levels following vaccination against COVID-19, FT adds. More than 150 people there received a fourth vaccine dose, which lead researcher Gili Regev-Yochay tells Bloomberg did boost antibody levels, but only provided partial protection against Omicron infections. This, FT says, suggests that the antibody level needed to protect against Omicron infections is very high. Still, that people in the trial who became infected with Omicron had slight or no symptoms, Regev-Yochay notes at Bloomberg.
Israel, Bloomberg says, has begun offering fourth SARS-CoV-2 vaccine doses to people over the age of 60 years and people who are immunocompromised. "The decision to allow the fourth vaccine to vulnerable populations is probably correct and it may give a little benefit — but not enough to support the decision to give it to all of the population," Regev-Yochay tells FT.