Pfizer Covid-19 Vaccine Works Against Mutations Found in U.K, South Africa Variants, Lab Study Finds

By Daniela Hernandez
Jan. 27, 2021 9:56 pm ET

A Pfizer Inc. laboratory study found that coronavirus mutations identified in the U.K. and South Africa had only small impacts on the effectiveness of antibodies generated by the company’s Covid-19 vaccine.

The antibodies were slightly less effective against mutations in the variant identified in South Africa, according to the study. It was posted Wednesday on the online server bioRxiv, which publishes scientific papers before they have been peer-reviewed.

Researchers have been racing to assess whether Covid-19 vaccines and drugs will still work against new variants, as governments roll out shots they hope will allow schools, businesses and other establishments to reopen.

Pfizer’s findings are consistent with other preliminary results reported in recent weeks by several research groups looking at the effectiveness of available vaccines against the new variants.

The research is still preliminary, however. Pfizer’s study was conducted in a lab and tested only a subset of mutations found in the variants, but not the variants themselves. Also, the researchers didn’t assess whether their results were statistically significant.

Yet these and other results suggest that the impact of the variants on the shots will be “relatively modest, which is good news for the vaccines,” said Jason McLellan, a structural biologist at the University of Texas at Austin who has studied how coronavirus proteins interact with antibodies and wasn’t involved in the Pfizer study.

Pfizer said the “findings do not indicate the need for a new vaccine to address the emerging variants.” The company said, however, that it and partner BioNTech SE BNTX -7.36% were prepared to respond to a vaccine-resistant version of the virus.

The Pfizer-BioNTech vaccine uses a new technology named messenger RNA, after the molecular couriers of genetic instructions, which allows developers to make more rapid changes to their vaccines than more traditional techniques. The other vaccine authorized in the U.S., from biotech Moderna Inc., also uses mRNA technology.

A recent preliminary study by Moderna, in collaboration with scientists at the U.S. National Institutes of Health, showed antibodies generated by its vaccine were less effective at binding the mutated spike proteins of the South African variant. The researchers didn’t find a difference for the U.K. variant’s spike proteins. The coronavirus uses its spike proteins, which stud its surface, to enter and infect cells. The proteins are key targets of antibodies.