A second booster of COVID-19 vaccines from Pfizer and Moderna failed to prevent infections of the omicron variant, according to a preliminary study by a hospital in Israel.
The vaccines lifted antibodies “even a little bit higher than what we had after the third dose,” said Gili Regev-Yochay, director of the Infectious Diseases Unit, at Israel’s Sheba Medical Center, according a Reuters report Tuesday. “Yet, this is probably not enough for the Omicron.”
The unpublished study looked at the effect of a second Pfizer-BioNTech PFE, -1.06% BNTX, -3.44% booster on 154 people after two weeks and a second Moderna MRNA, -2.59% booster among 120 people following one week. The vaccinated group was then compared to a control group with no fourth booster. The Moderna participants had previously received three Pfizer boosters.
“We know by now that the level of antibodies needed to protect and not to got infected from Omicron is probably too high for the vaccine, even if it’s a good vaccine,” said Regev-Yochay.
Read: Moderna aims for COVID/flu booster in 2023, but Fauci and other virus experts warn of challenges to come this year
Israel began rolling out fourth COVID vaccines to those over 60 and health workers in early January to combat surging cases due to the omicron variant.