Two studies showed the vaccine to be more than 95 percent effective at protecting against severe disease or death from the variants first identified in South Africa and the U.K.
The Pfizer-BioNTech coronavirus vaccine is extraordinarily effective at protecting against severe disease caused by two dangerous variants, according to two studies published Wednesday.
The studies, which are based on the real-world use of the vaccine in Qatar and Israel, suggest that the vaccine can prevent the worst outcomes — including severe pneumonia and death — caused by B.1.1.7, the variant first identified in the U.K., and B.1.351, the variant first identified in South Africa.
“This is really good news,” said Dr. Annelies Wilder-Smith, an infectious disease researcher at the London School of Hygiene and Tropical Medicine. “At this point in time we can confidently say that we can use this vaccine, even in the presence of circulating variants of concern.”
Previous research suggested that B.1.1.7 is more infectious and more deadly than other variants, but that vaccines still worked well against it. But vaccines appeared to be less effective against B.1.351, according to earlier studies.
One of the new studies, which appeared in the New England Journal of Medicine, is based on information about more than 200,000 people that was pulled from Qatar’s national Covid-19 databases between Feb. 1 and March 31.
During that time, the variants were widespread there: Sequencing conducted between Feb. 23 and March 18 suggested that roughly half of the coronavirus infections in that period were caused by B.1.351 and 44.5 percent were caused by B.1.1.7.
In multiple analyses, the researchers found that the vaccine was 87 to 89.5 percent effective at preventing infection with B.1.1.7 among people who were at least two weeks past their second shot. It was 72.1 to 75 percent effective at preventing infection with B.1.351 among those who had reached the two-week point.
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