The Pfizer/BioNTech Covid-19 Vaccine Is Less Effective Against The South African And UK Variants Than Against The Original Virus, According To A New “Real-World” Study From Israel
Thanks to an extensive vaccination program in Israel and diligent follow-up of those vaccinated, we have a bigger glimpse of how the Pfizer/BioNTech is performing against variants.
Simultaneous measurements of the frequency of infection in carefully matched unvaccinated control populations allowed the scientists to calculate that the vaccine was eight times more protective against the wild type than the B1.351 variant. Similar studies showed that the vaccine is about 2.5 times more effective against the wild type than it is against the B 1.1.7 (UK) variant. The authors caution that although the direction of the protective effect against the three types of virus is clear, the actual magnitude of the difference is only approximate due to the limited number of breakthrough cases.
In seeking to explain their observations the authors write, "From a biological point of view, the breakthrough cases observed in this study might either be due to immune evasion of both strains, or the ability of B.1.17 to create higher viral loads"
In commenting on their findings Adi Stern of Tel Aviv University was quoted as saying “We found a disproportionately higher rate of the South African variant among people vaccinated with a second dose, compared to the unvaccinated group. This means that the South African variant is able, to some extent, to break through the vaccine’s protection.”
South African variant may 'break through' Pfizer vaccine protection, but vaccine highly effective, Israeli study says
The coronavirus variant discovered in South Africa can break through the protection provided by Pfizer Inc and BioNTech's COVID-19 vaccine to some extent, a real-world data study in Israel found. However, the variant's prevalence in Israel is very low and the vaccine remains highly effective.
They have been testing a third dose of their shot as a booster, and have said they could modify the shot to specifically address new variants if needed.
They also said the research was not intended to deduce overall vaccine effectiveness against any variant, since it only looked at people who had already tested positive for COVID-19, not at overall infection rates.以色列玩数字游戏？不公布有效性数字(即使不准确）是不是因为太低？
Pfizer declined to comment on the Israeli study.