The study, carried out by Sheba Medical Center and the Health Ministry’s Central Virology Laboratory, compared the blood of 20 people who had received two vaccine doses 5-6 months earlier to the same number of individuals who had received a booster a month before.

“People who received the second dose 5 or 6 months ago do not have any neutralization ability against the Omicron. While they do have some against the Delta (strain),” Gili Regev-Yochay, director of the Infectious Diseases Unit at Sheba, told reporters.

“The good news is that with the booster dose it increases about a hundred fold. There is a significant protection of the booster dose. It is lower than the neutralization ability against the Delta, about four times lower,” she said.