Booster shots not good enough for Omicron

A landmark Israeli trial is expected to show that four shots of vaccine didn't stop infection by the Omicron variant, according to a study official.

While the extra dose of either Pfizer of Moderna vaccine seemed to have some effect, rates of infection in the study were not substantially different to those who had three doses of Pfizer, the study official said.

Gili Regev-Yochay, a lead investigator on the study, told reporters that "the vaccine is excellent against the Alpha and Delta," but the study found that "for Omicron, it's not good enough," The Times of Israel reported Monday evening.

The investigator did not release data from the trial, noting that the results are preliminary. But she said she shared the early findings as there was a large public interest, per The Times of Israel.

The findings, if confirmed and vetted by other scientists after publication, could bolster calls for the development of a new version of the COVID-19 vaccines. Some new types of vaccines are already in the early stages of development.

The Israeli trial, launched by the Sheba Medical Center a month ago, is investigating the effect of the Pfizer booster in 154 people and the Moderna booster in 120 people.

It found that there was an "increase in antibodies" among those who got the fourth shot.

But Regev-Yochay said: "we see many infected with Omicron who received the fourth dose. Granted, a bit less than in the control group, but still a lot of infections".