The Pfizer-BioNTech coronavirus vaccine provides strong protection against two concerning variants of the virus, including the one that has most worried scientists because it can evade parts of the immune response, according to new data from Qatar.
The study, published as a letter in the New England Journal of Medicine, found that the Pfizer-BioNTech vaccine was about 90 percent effective at blocking infections caused by the B.1.1.7 variant, a more transmissible version of the virus now fueling outbreaks around the world. That encouraging finding was not a surprise, but the study also found that efficacy eroded only slightly, to 75 percent, against the B.1.351 variant that was first detected in South Africa.
The B.1.351 variant carries mutations that help it elude some antibodies and as a result is considered by many experts the most challenging variant among those that have been identified. Because the Pfizer-BioNTech vaccine and one from the biotechnology company Moderna were tested in clinical trials before that variant emerged, it had remained unclear until now whether protection would be eroded by the variant. While the new study suggests the vaccine is somewhat less protective against the variant, it offered strong protection, particularly against severe, critical or fatal cases of covid-19, the illness caused by the virus. Continue reading.