JERUSALEM – The coronavirus variant discovered in South Africa may “break” to some extent the Pfizer / BioNTech COVID-19 vaccine, according to a study of real data in Israel, although its prevalence in the country is low and the research has not been the same – revised.
The study, published Saturday, compared nearly 400 people who had tested positive for COVID-19, 14 days or more after receiving one or two doses of the vaccine, against the same number of unvaccinated patients with the disease. It coincided with age and gender, among other characteristics.
The South African variant, B.1.351, was found to account for approximately 1% of all COVID-19 cases in all people studied, according to the Tel Aviv University study and the largest healthcare provider. of Israel, Clalit.
But among patients who had received two doses of the vaccine, the prevalence rate of the variant was eight times higher than that of the unvaccinated: 5.4% versus 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 Britain that has come to include almost all cases of COVID-19 in Israel, the researchers.
“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 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 due to its rarity in Israel.
They also said the research was not intended to deduce the overall effectiveness of the vaccine against any variant, as they 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 comment outside of business hours.
Companies said on April 1 that their vaccine was about 91% effective in preventing COVID-19, citing updated test data that included inoculated participants for up to six months.
Regarding the South African variant, they said that among a group of 800 student volunteers in South Africa, where B.1.351 is widespread, there were nine cases of COVID-19, which occurred among participants who obtained the placebo. Of these nine cases, six were from people infected with the South African variant.
Some previous studies have indicated that the Pfizer / BioNTech trait was less potent against variant B.1.351 than against other coronavirus variants, but still offered robust defense.
While the results of the study may cause concern, the low prevalence of the South African strain was encouraging, according to Stern.
“Even if the South African variant opens up vaccine protection, it has not spread widely to the population,” Stern said, adding that the British variant could “block” the spread of the South strain. African.
Nearly 53% of Israel’s 9.3 million population has received Pfizer doses. Israel has largely reopened its economy in recent weeks, while the pandemic appears to be receding, with rates of infection, serious illness and hospitalizations falling sharply. About a third of Israelis are under the age of 16, meaning they are not yet eligible for prey.