Variant can 'break through' Pfizer vaccine

Researchers in Israel say the novel coronavirus variant first discovered in South Africa is able to "break through" Pfizer/BioNTech's vaccine "to some extent".

The variant managed to avoid protection offered by two doses of the vaccine to some degree, according to a first-of-its-kind real-world data study by Tel Aviv University and Israel's largest healthcare provider, Clalit.

Israel has used the Pfizer vaccine almost exclusively to vaccinate millions of citizens, The Times of Israel reported.

Researchers at the university explained that the mutation seems to be more able to evade the vaccine than the original novel coronavirus strain and the variant first identified in Britain.

The study compared 400 people who tested positive for COVID-19, after being vaccinated more than two weeks earlier, against the same number of unvaccinated patients with the disease, Reuters news agency reported.

The variant first identified in South African, also known as B.1.351, was found to make up about 1 percent of all the COVID-19 cases studied.

The research showed that the prevalence of the strain among vaccinated individuals who were infected despite their inoculation was eight times higher than its prevalence in the unvaccinated infected population.

The research, which has not yet been peer reviewed, matched age and gender, "among other characteristics".

"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 through the vaccine's protection," said Tel Aviv University's Adi Stern.

But the study only included a small sample of people infected with the variant first identified in South Africa, as it is rare in Israel, researchers noted, adding that the low prevalence of the South African strain was encouraging.

The scientists also said that they believe the variant first identified in Britain, which comprises nearly all COVID-19 cases in Israel, could be blocking the variant first found in South Africa from spreading.

"Even if the South African variant does break through the vaccine's protection, it has not spread widely through the population," said Stern.

Nearly 53 percent of Israel's 9.3 million population has received both doses of the Pfizer-BioNTech vaccine, according to the government.

Infection rates, severe illness and hospitalizations have dropped in Israel in recent weeks, and the economy has mostly reopened, Reuters said.

Pfizer and BioNTec had stated previously, on April 1, that their vaccine was "about 91 percent effective at preventing COVID-19", noting latest trial data that included participants vaccinated for up to six months.