Friday, 29 March, 2024
HomeCoronavirus WatchPfizer-BioNTech vaccine may be less effective against SA variant — Israeli study

Pfizer-BioNTech vaccine may be less effective against SA variant — Israeli study

The coronavirus variant discovered in South Africa can "break through" Pfizer-BioNTech's COVID-19 vaccine to some extent, a study in Israel has found. The South African coronavirus variant managed to penetrate the protection offered by two doses of the Pfizer-BioNTech vaccine to some degree, though it remains unclear just how much efficacy is lost, it said.

The research compared nearly 400 people who tested positive for COVID-19 two weeks or more after they received one or two doses of the vaccine, against the same number of unvaccinated patients with the disease. It matched age and gender, among other characteristics. The South African variant, B.1.351, was found to make up about 1% of all the COVID-19 cases across all the people studied, according to the study by Tel Aviv University and Israelʼs largest healthcare provider, Clalit. But among patients who had received two doses of the vaccine, the variant's prevalence rate was eight times higher than those unvaccinated- 5.4% versus 0.7%

This suggests the vaccine is less effective against the South African variant, compared with the original coronavirus and a variant first identified in Britain that has come to comprise nearly all COVID-19 cases in Israel, the researchers said.

However, News24 reports, the researchers cautioned that the study only had a small sample size of people infected with the South African variant because of its rarity in Israel.

News24 reports that the companies said on 1 April that their vaccine was about 91% effective at preventing COVID-19, citing updated trial data that included participants inoculated for up to six months.

With respect to the South African variant, they said among a group of 800 study volunteers in South Africa, where B.1.351 is widespread, there were nine cases of COVID-19, all of which occurred among participants who got the placebo.

News24 reports that some previous studies have indicated the Pfizer-BioNTech shot was less potent against the B.1.351 variant than against others of the coronavirus, but still offered a robust defence.

 

Full News24 report (Open access)

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