New research suggests Pfizer’s COVID-19 vaccine can protect against a mutation found in the two more-contagious variants of the coronavirus that have erupted in Britain and South Africa.
The study was preliminary and did not look at the two other major vaccines being used in the West — Moderna’s and AstraZeneca’s. But it was reassuring, given questions of whether the virus could mutate to defeat the shots on which the world has pinned its hopes.
“There’s no reason to think the vaccines won’t work just as well on these strains,” said Dr. Frederic Bushman of the University of Pennsylvania, who tracks how the virus mutates.
The mutated version circulating in Britain has also been detected in the U.S. and numerous other countries. That and the variant seen in South Africa are causing global concern because they appear to spread more easily — although how much more isn’t yet known.
“A mutation will change one little place, but it’s not going to disrupt binding to all of them,” Bushman explained.
The study looked at one modification to the spike protein that both variants share, called N501Y, that is believed responsible for the easier transmission. Pfizer and researchers from the University of Texas Medical Branch in Galveston conducted laboratory tests to see if that mutation could thwart the vaccine.
They used blood samples from 20 people who received the vaccine, made by Pfizer and its German partner BioNTech, during a large trial of the shots. Antibodies from those recipients fended off the virus in lab dishes, according to the study, posted late Thursday on an online site for researchers.
The findings have not yet been reviewed by outside experts, a key step for medical research.
Viruses constantly undergo minor changes as they spread from person to person.
Dr. Anthony Fauci, the top U.S. infectious disease expert, told The Associated Press this week that the coronavirus variants don’t appear to block vaccine-induced antibodies but that testing to be sure of that is underway in the U.S. and elsewhere.
British scientists have likewise said the variant found in the U.K. -– which has become the dominant type in parts of England — still seems to be susceptible to vaccines.
South Africa has not started mass vaccinations.
If the virus eventually mutates enough that the vaccine needs adjusting — much like flu shots are adjusted most years — tweaking the recipe wouldn’t be difficult for vaccines made with newer technologies. Both the Pfizer-BioNTech and Moderna vaccines are made with a piece of the virus genetic code that is simple to switch.
The coronavirus isn’t changing as rapidly as other viruses such as flu or HIV, and its structure is more stable than the flu’s, Bushman said, although that will need to be tracked.
Meanwhile, U.S. health regulators said Friday they think there is a low risk that the new variants could hurt the accuracy of hundreds of COVID-19 tests on the market.
Food and Drug Administration chief Stephen Hahn said the agency has been monitoring the virus since the summer for any mutations that could skew testing results. So far, most tests that look for the virus’s genetic code remain accurate, but the agency is also studying whether viral mutations could affect rapid tests that look for COVID-19 proteins, called antigens.
