The South African variant escapes protection of the Pfizer/BioNTech vaccine better than other forms of the virus, Israeli experts said Sunday.
The study by Tel Aviv University and Clalit Health Services, Israel’s largest healthcare provider, compared patients with COVID, 400 unvaccinated patients to 400 partially or fully vaccinated ones.
Less than one percent of COVID cases in Israel were due to the South African variant. However, among the 150 people who were fully vaccinated yet had developed COVID, “the prevalence rate [of the B.1.351 variant] was eight times higher than the rate in the unvaccinated [individuals],” the authors wrote.
“This means that the Pfizer-BioNtech vaccine, though highly protective, probably does not provide the same level of protection against the South African (B.1.351) variant of the coronavirus,” the authors added.
“The South African variant is able, to some extent, to break through the vaccine’s protection,” said professor Adi Stern of Tel Aviv University’s Shmunis School of Biomedicine and Cancer Research, one of the study’s authors.
Prof Stern said that the study did not assess whether the eight people infected with the South African developed severe COVID.
“Since we found a very small number of vaccinees infected with B.1.351, it is statistically meaningless to report disease outcomes,” he said.
The possibility of reduced protection was already hinted at in two studies conducted by principal vaccine manufacturers Pfizer/BioNTech and Moderna, showing that the presence of antibodies after vaccination was less pronounced in people exposed to the B.1.351 variant. This marked the first real-world assessment of B.1.351’s ability to bypass a vaccine.
Israel’s vaccination campaign has seen 5.3 million people receive a first dose, while 4.9 million, or 53 percent of the population, have had two shots.
Clalit’s earlier study on 1.2 million Israelis found that the Pfizer/BioNTech jab gave 94 percent protection against COVID.
Israel has eased many of its restrictions since its vaccine rollout, but various measures remain in place including mask-wearing and a “green passport” system that allows vaccinated people access to certain locations. With cases down 97% since January, Israel may have achieved “herd immunity”, according to Eran Segal, a computational biologist at the Weizmann Institute of Science.
Ran Balicer of Clalit said inoculations, plus mask-wearing and other safety measures had likely helped contain the B.1.351 variant, despite its apparent ability to break through the Pfizer/BioNTech vaccine.
A combination of all these factors “are most likely… preventing the virus strains, including the South African one, from spreading” significantly in Israel, he said.
“As we taper down the non-pharmaceutical interventions, we must do so gradually to ensure we do not cross a threshold that would enable these variants to spread.”
Source: Medical Xpress
