[ad_1]
A single injection of the BioNTech / Pfizer vaccine produces a robust antibody response within weeks, according to Israeli data that could help determine whether scarce global supplies can be stretched by delaying second doses.
At the Rambam Healthcare Campus in northern Israel, 91% of the 1,800 doctors and nurses who received the two-dose vaccine showed a major presence of antibodies 21 days after their first injection, before receiving the vaccine. second dose, according to Michael Halberthal, chief director of the hospital. Another 2 percent showed a moderate presence of antibodies.
“If 93 percent had a significant response three weeks after the first injection, that raises a good question, which is that you might prefer to use the first injection on more people,” said Dr Halberthal.
At Sheba Medical Center, similar serological tests at different intervals showed that at least 50% of the staff had an antibody level ‘above the threshold’ two weeks after the first stroke, said Arnon Afek, associate managing director. of the hospital chain.
Data from both hospitals are based on individual antibody responses to the vaccine and do not provide a definitive assessment of the efficacy of a single vaccine. BioNTech / Pfizer clinical trials were based on two injections, 21 days apart, and did not measure antibody response. Pfizer said it couldn’t comment on the independent studies.
However, the first findings are likely to encourage scientists who have argued that the time between the first and second doses of Covid vaccines could be extended in order to stretch limited stocks.
“This relates to what is currently in dispute in the UK, whether it is to continue to give only a first dose, so people are given certain levels of immunity or to move on to the second,” he said. said Mr. Afek,
Israel has enough vaccines and should not change its strategy. He plans to inoculate the entire adult population by mid-March. “The question of whether the first blow is enough will not be answered outside of Israel,” Afek said. “Our policy is to strike it twice, but the data we have collected is important.”
Israel’s rapid vaccination program is closely monitored by epidemiologists looking for data on the actual effectiveness of vaccines and the impact of vaccine-induced immunity on infection rates. The country of 9 million people has already administered the first vaccines to more than a quarter of the population, the highest vaccination rate in the world. It administered a second vaccine to approximately 850,000 people, including 80% of the population over 60.
Frontline health workers were among the first to be vaccinated in Israel, providing a large sample of an at-risk population dating back to the end of December.
Stephen Evans, professor of pharmacoepidemiology at the London School of Hygiene & Tropical Medicine, said the UK, which chose to space out the first and second doses of the BioNTech / Pfizer vaccine beyond the recommended 21 days, was leading its own studies.
“The UK will soon have its own data showing effectiveness after the first dose for the various vaccines currently in use and any policy changes should wait for more solid data,” he said.
[ad_2]
Source link