A
new study by Israeli researchers found that a South African variant of COVID may put people who have been vaccinated with the Pfizer-BioNTech vaccine at higher risk of
breakthrough infection compared to unvaccinated people.
The study also showed an increased incidence of the UK variant in those who received one dose of the Pfizer shot.
The study, released April 10, reviewed the positive COVID-19
test results of 800 people — 400 people who tested positive for COVID 14 days or more after they received one or two doses of the
Pfizer vaccine against 400 unvaccinated people to see if those vaccinated were more likely to be infected with the UK or South African variant compared with unvaccinated individuals.
The South African variant, B.1.351, was found to make up about 1% of all COVID cases across all the people studied, according to the study by
Tel Aviv University and Israel’s 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 in those unvaccinated — 5.4% versus 0.7%,
Reuters reported.
The research suggests the vaccine is less effective against the South African variant, compared with the original COVID variant and a variant first identified in Britain that had comprised nearly all COVID cases in Israel,
researchers said.
“We found a disproportionately higher rate of the South African variant among people vaccinated with a second dose, compared to the unvaccinated group,”
said Tel Aviv University’s Adi Stern, who headed the research. “This means that the South African variant is able, to some extent, to break through the vaccine’s protection.”
“Based on patterns in the general population, we would have expected just one case of the South African variant, but we saw eight,” Stern
told The Times of Israel. “Obviously, this result didn’t make me happy.”
