A syringe and a bottle reading "Covid-19 Vaccine" next to the Pfizer company logo in Jerusalem on December 10, 2020. (Photo by Olivier Fitoussi/Flash90) News Israel Israeli study: Double dose of Pfizer can’t fight Omicron, but booster helps Facebook Twitter Email SMS WhatsApp Share By Abigail Klein Leichman, ISRAEL21c | December 15, 2021 Two full doses of the Pfizer-BioNTech Covid-19 vaccine are not effective at all against the Omicron variant of the coronavirus, but a third booster shot helps, said Dr. Gili Regev-Yochay, director of the Infectious Disease Epidemiology Unit at Sheba Medical Center, at a Saturday night Zoom press conference. In cooperation with the Health Ministry’s Central Virology Lab at Sheba, the study compared bloodwork from 20 Sheba healthcare workers who received two doses five or six months ago (but not a third dose) with another 20 who received the booster one month ago. “We compared the ability to neutralize the Omicron from these sets of bloods and we have good news and bad news,” said Regev-Yochay. “The bad news is that people who received the second dose five or six months ago do not have any neutralization ability whatsoever against the Omicron, while they do have some against the Delta and much more, even, against the wild [original] type,” she said. “That is very worrisome.” The good news: The booster dose increases protection against Omicron about a hundredfold. RELATED: Omicron variant scuttles major Stanford Israel trip as borders close “There is significant protection from the booster dose. It is lower than the neutralization ability against the Delta – about four times lower – and against the wild type, but we are very optimistic,” she said. “We still don’t know whether this will decrease with time, and we’ll have to check that,” Regev-Yochay added. She also does not know whether people inoculated with two doses less than five months ago have immunity against the Omicron variant. The results of the small study are to be peer reviewed and published in the New England Journal of Medicine. They are similar to findings presented by Pfizer and BioNTech earlier in the week. In response to the Sheba results, Israel’s Health Ministry reportedly is considering a recommendation to get a third dose only three months after the second. “It looks like with Omicron there is a chance that people with the booster could get infected, but have much less chance of getting seriously infected,” Regev Yochay said. Abigail Klein Leichman Abigail Klein Leichman is associate editor of ISRAEL21c. ISRAEL21c Content distributed by ISRAEL21c Also On J. Israel Israeli panel recommends 4th Covid vaccine for all adults over 18 Israel An Israeli doctor tested positive for Omicron, but infected few contacts Israel Israel begins administering 4th Covid vaccine dose Bay Area Facing omicron spike, Bay Area synagogues weigh their options Subscribe to our Newsletter Enter Email Sign Up