A research team from the University of Oxford announced Thursday that the AstraZeneca and Pfizer-BioNTech vaccines against the coronavirus may provide more protection against the so-called Brazilian strain than was initially thought.
The study has not yet been peer-reviewed and was carried out by the university involved in the development of the AstraZeneca shot.
The researchers found that the vaccines provide protection against the Brazilian P1 coronavirus variant that first became dominant in the Amazonian city of Manaus, as it may be less resistant to antibodies.
“These data suggest that natural and vaccine-induced antibodies can still neutralize these variants, but at lower levels,” the researchers said in a statement, according to Sky News. “Importantly, the P1 ‘Brazilian’ strain may be less resistant to these antibodies than first feared.”
The study used blood samples from people who have natural antibodies after they were infected with the coronavirus, as well as those who have received the Pfizer-BioNTech or AstraZeneca vaccines.
“The results suggest that P1 might be less resistant to vaccine and convalescent immune responses than B1351 [South Africa], and similar to B117 [UK],” Prof. Gavin Screaton, lead scientist on the study, told the Guardian.
“It found a nearly three-fold reduction in the level of virus neutralization by the antibodies generated by the Oxford and Pfizer vaccines for the [UK] and Brazil variants when compared to the original strain, and a nine-fold and 7.6-fold reduction respectively against the South Africa variant,” Screaton said.
Earlier this month, researchers on a study carried out by Pfizer-BioNTech and researchers from the University of Texas Medical Branch said the Pfizer-BioNTech vaccine is able to defeat the Brazilian strain.
They wrote that the vaccine was roughly as effective against the Brazilian strain as it is against another mutation that originated in Britain and is now the most prevalent strain in Israel, and “robust but lower” in dealing with a South African variant.
As countries around the world rush to vaccinate people, concerns have risen that more transmissible variants may have greater resistance to existing vaccines.
Pfizer said in February it would test a new version of its vaccine aimed at countering the South African variant, as well as the effectiveness of a third dose against other mutations.
Brazil has recorded almost 280,000 deaths from the virus. The toll has been worsening lately, with the nation currently averaging more than 1,800 deaths each day while health care systems of major cities are on the brink of collapse.
Agencies contributed to this report.