The South African variant of the coronavirus is more capable of “breaking through” the Pfizer-BioNTech vaccine than other variants, Israeli scientists found in a first-world real-world study.
Israel has used the Pfizer vaccine almost exclusively to vaccinate millions of citizens, with a version of Moderna based on similar innovative mRNA technology, which is used minimally.
A team from Tel Aviv University and the Clalit Healthcare Organization set up the blots of 150 Israelis who tested positive for COVID-19 despite the vaccination.
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In their study, the prevalence of the South African tribe among vaccinated individuals who were infected despite their vaccination was eight times higher than its prevalence in the non-vaccinated population. Although the number of such infections among the vaccinated was relatively small, the findings indicated that this variant was much more successful in getting the defense of vaccinated by other strains.
“Based on patterns in the general population, we would have expected only one case of the South African variant, but we have seen eight,” said prof. Adi Stern, head of the research, told The Times of Israel. “Clearly, this result did not make me happy.”
A coronavirus testing center in Israel run by Magen David Adom. (Flash90)
She said the results showed that the South African variant, compared to the original strain and the British variant, “could break through the protection of the vaccine.” However, she said the sample size is too small to determine its increased capacity.
“We can say that it is less effective, but more research is needed to determine exactly how much is,” she said.
Professor Ran Balicer, Head of Innovation at Clalit, Israel’s largest healthcare provider, in Tel Aviv, on 10 June 2020. (EMMANUEL DUNAND / AFP)
Prof. Ran Balicer, director of research at Clalit, said the study was ‘very important’.
“This is the first in the world based on actual data, which shows that the vaccine is less effective against the South African variant, compared to the original virus and the British variant,” he said.
Balicer added that the results require constant vigilance against the coronavirus, including social removal and wearing masks in indoor spaces to prevent infection.
“These preliminary findings necessitate continued attention to the spread of this strain in Israel, and emphasize the need for epidemiological monitoring and systematic sequencing to contain further spread of the South African variant in Israel,” he said.
Students receive COVID-19 vaccine injections at Amal High School in the southern city of Beersheba, March 17, 2021. (Flash90)
The research, which was posted online but has not yet been peer-reviewed, is likely to raise questions about Pfizer’s own actual study, which found that the vaccine was 100 percent effective in South Africa, although the local strain common.
The Tel Aviv research seems to confirm a recent study by the Ben-Gurion University of the Negev, which found that the vaccine response is less effective against the South African variant. This was concluded by analyzing blood samples, while the new research is based on actual sequence of test results.
Prof. Adi Stern of the University of Tel Aviv’s School of Molecular Cell Biology and Biotechnology (courtesy of Tel Aviv University)
Stern emphasized that the South African variant remains uncommon in the vaccinated population, and emphasized that the study does not indicate exactly the level of protection against the variant, because its prevalence in Israel is very low – about 1% of all cases.
The study also examined the so-called British variant’s ability to break through the defense of the vaccine compared to the original strain. No difference was found in the ability of the British variant to infect fully vaccinated individuals after two doses. However, it was more able to infect individuals who had been partially vaccinated than the original.
In Israel, the massive spread of the non-infectious British variant beginning in January – to the point that it now accounts for more than 90% of COVID cases – is responsible for a major wave in the first months of the year, which delays the outcome of the pandemic.
But Stern said it quite possibly had a silver lining: in the battle between variants, the British are much stronger and possibly keep the South African on point.
“It is possible that the widespread distribution of the British variant is blocking the distribution of the South African variant,” she said. “Because it spread so effectively, the South African variant basically did not allow it to spread – it won the competition.”
With more than half the population fully vaccinated, the pandemic is now declining, with new daily infections in the low hundreds.
