Omicron significantly reduced Covid antibody protection in a small study of Pfizer vaccine recipients
Nurse Mary Ezzat gives Jessica M. a Pfizer COVID-19 booster shot at UCI Medical Center in Orange, CA, on Thursday, August 19, 2021.
Jeff Gritchen | MediaNews Group | Sign up for Orange County via Getty Images
South African scientists say the Covid omicron variant significantly reduces the amount of antibodies produced by the Pfizer and BioNTech vaccines, although those who have recovered from the disease and received a booster shot will likely be more protected. from severe illness, according to a small preliminary study published Tuesday.
Professor Alex Sigal with the African Institute for Health Research and a team of scientists tested blood samples from 12 people previously vaccinated with the Pfizer/BioNTech vaccine, looking specifically at the levels of antibodies produced by the vaccine. could neutralize the new variant – that is, block its ability to infect cells.
They found that the ability of their antibodies to neutralize the omicron variant was 41-fold reduced compared with the original virus, a significant reduction in its performance over the original ancestor strain as well as other variants. , according to a preprint of the study. has not been peer-reviewed. The antibodies produced by the vaccine were more than three times less likely to neutralize the beta variant that previously dominated South Africa, suggesting that omicrons are much better able to evade protection.
“The results we present here with Omicron show a much broader possibility of escape” than the beta variant, the researchers write. “Previous infection, followed by vaccination or booster shot has the potential to increase neutralization and potentially protect against severe disease in Omicron infections.”
The previous study had yet to be peer-reviewed, and it tested 14 plasma samples from 12 vaccinated people, six of whom had been previously infected. The scientists provided their Covid study before undergoing extensive peer-review because of the urgency of the pandemic.
Pfizer CEO Albert Bourla said early Friday that the company could develop a vaccine specifically targeting omicrons by March 2022 if needed. Bourla said it will take several weeks for more firm data to be available on whether current vaccines provide sufficient protection against this variant.
Pfizer’s CEO previously told CNBC that the protection offered by the company’s two-dose vaccine is likely to drop some in the face of omicrons.
The South African scientists also found that omicrons attach to the same receptor, called ACE2, to infect human lung cells that previous variants had used.
This is an evolving story. Please check back for updates.
