Study says South African variant could “breach” Pfizer vaccine protection

Study says South African variant could “breach” Pfizer vaccine protection


The variant of coronavirus discovered in South Africa may to some extent breach the protection of Pfizer Inc and BioNTech’s COVID-19 vaccine, a real-world data study in Israel found. However, the prevalence of the variant in Israel is very low and the vaccine remains highly effective.

Read more on Study says South African variant could “breach” Pfizer vaccine protection…


The variant of coronavirus discovered in South Africa may to some extent breach the protection of Pfizer Inc and BioNTech’s COVID-19 vaccine, a real-world data study in Israel found. However, the prevalence of the variant in Israel is very low and the vaccine remains highly effective.

The study was published on the medRxiv pre-print site on April 9th ​​and was not peer-reviewed. Nearly 400 people who tested positive for COVID-19 after receiving a dose or two of the vaccine were compared with the same number of unvaccinated patients with the disease. It matched age and gender, among other things.

The South African variant B.1.351 accounts for around 1% of all COVID-19 cases in all people examined, according to the study by Tel Aviv University and the largest Israeli health service provider Clalit. In patients who received two doses of the vaccine, the prevalence rate of the variant was eight times higher than in non-vaccinated patients – 5.4% versus 0.7%.

This suggests that the vaccine against the South African variant is less effective than the original coronavirus and a variant first identified in the UK that now includes almost all COVID-19 cases in Israel, the researchers said.

The researchers said the study was not intended to assess the vaccine’s overall effectiveness against any variant, as it only looked at people who had already tested positive for COVID-19, not overall infection rates.

Separate real-world Israeli studies on the vaccine’s overall effectiveness, including Clalit, have shown the Pfizer shot to be over 90% effective.

“We found a disproportionately higher rate of the South African variant in people who were vaccinated with a second dose than the non-vaccinated group. This means that the South African variant can, to some extent, breach the protection of the vaccine,” said Tel Adi Stern from the University of Aviv.

In an update to the study published on April 16, the researchers found that within the group of people who received two doses, which included eight people, all B.1.351 infections within a week to 13 days after second shot occurred. None of them tested positive 14 days or more after the second dose.

“This could mean that there is a short window of susceptibility to B.1.351 infection that is limited to the immediate two weeks after the second dose – but we cannot be sure that this is actually the case,” said Ran Balicer from Stern and Clalit in an email until Sunday.

However, the researchers warned that due to its rarity in Israel, the study only had a small sample of people infected with the South African variant.

“The previous incidence of B.1.351 in Israel remains low and the effectiveness of the vaccine in the fully vaccinated people remains high,” the study said.

Pfizer declined to comment on the Israeli study. Pfizer and BioNTech on July 1 said their vaccine was 91% effective in preventing COVID-19, citing updated study data that included participants who had been vaccinated for up to six months.

They tested the third dose of their shot as a booster and said they could modify the shot to target new variants if needed.

Regarding the South African variant, they stated that among a group of 800 volunteers in South Africa, where B.1.351 is prevalent, there were nine cases of COVID-19, all of which occurred in participants who received the placebo. Of these nine cases, six were among people infected with the South African variant.

Some previous studies have shown that the Pfizer / BioNTech shot was less effective against the B.1.351 variant than against other variants of the coronavirus, but still offered strong defense.

While the study’s results may be cause for concern, the low prevalence of the South African strain was encouraging, according to Stern.

“Even if the South African variant breaks the vaccine’s protection, it has not spread widely among the population,” Stern said, adding that the British variant may “block” the spread of the South African tribe.

More than half of Israel’s 9.3 million residents have received both cans of Pfizer. Israel has largely reopened its economy in recent weeks as pandemic bulbs decline, with infections and hospital stays falling sharply.

.

COMMENTS