JERUSALEM (Reuters) – The coronavirus variant found in South Africa may “break” the COVID-19 Pfizer / BioNTech vaccine to some extent, a real Israeli study found, although its prevalence in the country is low and research has was evaluated by colleagues.
The study, released on Saturday, compared nearly 400 people who tested positive for COVID-19 14 days or more after receiving one or two doses of the vaccine to the same number of unvaccinated patients. It matched age and gender, among other features.
The South African variant, B.1.351, was found to account for approximately 1% of all COVID-19 cases in all subjects, according to a study by Tel Aviv University and Israel’s largest healthcare provider, Clalit.
But among patients who received two doses of vaccine, the prevalence rate of the variant was eight times higher than those who were not vaccinated – 5.4% compared to 0.7%.
This suggests that the vaccine is less effective against the South African variant compared to the original coronavirus and a variant first identified in the UK, which has come to cover almost all cases of COVID-19 in Israel, the 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. This means that the South African version is able, to some extent, to break the protection of the vaccine, “said Adi Stern of Tel Aviv University.
The researchers warned, however, that the study had only a small sample of people infected with the South African variant because of its rarity in Israel.
They also said that the research was not intended to deduce the overall effectiveness of the vaccine against any variant, as it only looked at people who had already tested positive for COVID-19, not the overall infection rates.
Pfizer and BioNTech could not be reached immediately for comments outside of business hours.
The companies said on April 1 that their vaccine was about 91% effective in preventing COVID-19, citing updated data from studies that included inoculated participants for up to six months.
Regarding the South African version, they said that among a group of 800 studied volunteers from South Africa, where B.1.351 is widespread, there were nine cases of COVID-19, all of which occurred among participants who received placebo. Of the nine cases, six were among individuals infected with the South African variant.
Some previous studies have shown that the Pfizer / BioNTech stroke was less severe against variant B.1.351 than against other variants of coronavirus, but still provided a robust defense.
While the results of the study may cause concern, the low prevalence of the South African strain has been encouraging, according to Stern.
“Even though the South African version penetrates through vaccine protection, it has not spread widely among the population,” Stern said, adding that the British version could “block” the spread of the South African strain.
Almost 53% of Israel’s 9.3 million population received both doses of Pfizer. Israel has largely reopened its economy in recent weeks, while the pandemic appears to be declining, with infection rates, severe illness and hospitalizations falling sharply. About a third of Israelis are under the age of 16, which means they are not yet eligible for shooting.
Reporting by Maayan Lubell; Edited by Pravin Char