Israeli researchers believe the South African coronavirus variant may be able to partially “break through” the Pfizer COVID-19 vaccine, reported Haaretz, citing a real-world data study released Saturday by Tel Aviv University and Clalit, the largest of Israel's four national healthcare providers. The study included some 400 people who tested positive for COVID more than two weeks after receiving either their first or second dose, as well as an equal number of unvaccinated COVID patients. The scientists who performed the experiment cautioned that the sample size was small, since the South African variant is uncommon in the country, and the research had not been peer reviewed.

"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," Adi Stern of Tel Aviv University told Haaretz. “Even if the South African variant does break through the vaccine's protection, it has not spread widely through the population,” Stern added, saying the British COVID variant could be “blocking” the wider spread of the South African strain.