A single uptake of the BioNTech / Pfizer vaccine, according to Israeli data, yields a robust antibody response within a few weeks that can help know if barely worldwide stock can be stretched by delaying the second doses.
According to Michael Halberthal, head of the Rambam Health Care Campus in northern Israel, 91 percent of the 1,800 doctors and nurses who received the two-dose vaccine showed a large presence 21 days after their first shot. CEO of the hospital. A further 2 percent showed a moderate presence of antibodies.
“If 93 percent had a major reaction three weeks after the first injection, it’s a good question that you would rather use the first injection on more people,” Dr Halberthal said.
At Sheba Medical Center, similar serological tests at various intervals showed at least 50 percent of staff with a level of antibodies ‘above the cut-off point’ two weeks after the first stab, said Arnon Afek, the director general of the hospital chain.
The data from the two hospitals are based on individual antibody responses to the vaccine and do not provide a definitive assessment of the efficacy of a single shot. BioNTech / Pfizer’s clinical trials were based on two shots, 21 days apart, and did not measure any antibody response. Pfizer said it could not comment on independent studies.
However, the early findings are likely to encourage scientists who have argued that the time between the first and second doses of Covid vaccines can be extended to stretch limited stocks.
“It’s about what’s currently being contested in the UK, whether to continue to give only a first dose so that people receive certain levels of immunity or to go to the second,” he said. Afek said
Israel has sufficient vaccine supplies and is not expected to change its strategy. It plans to vaccinate the entire adult population by mid-March. “The question of whether the first shot is enough will not be answered from Israel,” he said. Afek said. “Our policy is to give two shots, but the data we have collected is important.”
Israel’s rapid vaccination program is being closely monitored by epidemiologists looking for data on actual vaccine efficacy and the impact of immunization-induced immunity on infection rates. The country of 9 million people has already given more than a quarter of the population first shots, the highest vaccination rate in the world. It fired about 850,000 people, including 80 percent of the population over 60.
Frontline health care workers were one of the first to be vaccinated in Israel, and provided a large sample of an endangered population that lasted until the end of December.
Stephen Evans, professor of pharmacoepidemiology at the London School of Hygiene & Tropical Medicine, said the UK, which chose to place the first and second doses of BioNTech / Pfizer survey longer than the recommended 21 days, conducted its own studies has.
“The UK will soon have its own data showing efficacy after the first dose for the various vaccines currently in use, and any policy changes will have to wait for more robust data,” he said.