variant may ‘break through’ pfizer vaccine, study says

the south african variant of covid-19 has shown the ability to bypass the defences of the pfizer vaccine in a study of infected patients in israel.the research, which is still awaiting peer review, compared 400 people who had tested positive for the virus after receiving one or both shots of the vaccine to a similar number of infected people who had not been inoculated. it found that the south african variant, also known as b.1.135, was eight times more common in patients who had been fully vaccinated.the vexing variant is rare in israel — turning up in just one per cent of the 800 patients tested — but believed to be 60 per cent more transmissible than the original strain of covid-19. despite its low prevalence, the variant was found in 5.4 per cent of people who had received both doses of the pfizer vaccine compared to just 0.7 per cent of unvaccinated people. the findings show this particular variant is more resistant to inoculation, 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,” adi stern, one of the tel aviv university researchers, told abc news. “this means that the south african variant is able, to some extent, to break through the vaccine’s protection.”researchers said the research was limited by the rarity of the south african variant in israel and stressed the study did not ascertain overall vaccine effectiveness against any variant. it was also concerned with individuals who were already infected as opposed to trying to determine the overall rate of infection from the virus.pfizer and biontech did not immediately respond to the research, but the companies have previously pointed to another study of 800 volunteers in an area of south africa where the variant was widespread. after vaccination, there were only nine cases of covid-19 detected in the study — all from the placebo group — with six of the nine contracting the variant.
the low prevalence of the south african variant is good news amid the concerning findings in israel, stern said. just over half of israel’s 9.3 million residents have received both shots of the pfizer vaccine, drastically dropping the rates of infection, severe illness and hospitalization and allowing the country to largely reopen. “even if the south african variant does break through the vaccine’s protection, it has not spread widely through the population,” she said.pfizer and biontech said earlier this year that they were working on a potential third dose of their vaccine or some form of booster shot that could offer added protection to individuals as time wears on and more strains emerge. “the rate of mutations in the current virus is higher than expected,” said mikael dolsten, pfizer’s chief scientific officer. “it’s a reasonable probability that we would end up with regular boosts.”“and for potent vaccines, it may be that you need to do a strain change every few years.”dave yasvinski is a writer with healthing.cadon’t miss the latest in health. subscribe to healthing’s daily newsletter here.