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Pfizer’s COVID-19 vaccine successfully neutralizes the more contagious variant of the virus spreading rapidly in Brazil, according to a new laboratory study published in the New England Journal of Medicine.
Scientists with Pfizer and the University of Texas studied blood samples from people who had received both doses of Pfizer’s vaccine, finding that the two-shot regimen “efficiently” neutralized a version of the virus engineered to carry the same concerning mutations of the Brazilian variant, dubbed P.1. The samples were taken between two to four weeks after the subjects, participants in late-stage trials for the vaccine, received their second dose.
The P.1 variant has mutations in common with the COVID-19 strain first identified in South Africa, which are believed to make that strain of the virus more contagious and possibly able to escape immunity protection. But in previously published studies, Pfizer had found that its vaccine appeared to be effective against the more transmisible variants, including the South African strain; though blood samples from vaccinated people produced fewer neutralizing antibodies, there was still enough of a response to neutralize the South Africa strain.
The new study comes as public health experts warn that the more transmissible variants could drive yet another surge in COVID-19 cases. The newer Brazilian variant was first detected in January and has since spread from the Amazonian city of Manaus to multiple countries, including the United States. So far, 15 cases of the Brazilian variant have been reported in nine states, according to the U.S. Centers for Disease Control and Prevention.
“If you allow the virus to proliferate at the levels it is currently proliferating here, you open the door to the occurrence of new mutations and the appearance of even more lethal variants.” Miguel Nicolelis, a Duke University neuroscientist who is tracking the rampant outbreak in Brazil, told the Guardian last week. “Brazil is an open-air laboratory for the virus to proliferate and eventually create more lethal mutations.”