Pfizer, BioNTech Say Vaccine Can Beat a Mutation in New Virus Strains
Pfizer Inc. and BioNTech SE said a laboratory study suggests their jointly developed Covid-19 vaccine can overcome a mutation found in two new, fast-spreading variants of the coronavirus recently discovered in the U.K. and South Africa.
However, researchers behind the study, including some employed by the drug makers, said more work is needed to determine whether other mutations in the variants could pose problems for the shot. Crucially, the study didn't examine how the vaccine responds to another mutation, found only in the South African variant, that in other experiments has shown resistance to some antibodies the human body uses to fight off Covid-19.
It is normal for viruses to mutate, and most variants observed so far in the coronavirus sweeping the globe have made little difference to how it functions. But the British and South African variants, which have since spread to other countries, have worried scientists because of their unusually large number of mutations, especially in the spike protein, which the virus uses to attach to and infect human cells.
The test-tube study--done by researchers at the University of Texas Medical Branch and supported by Pfizer and BioNTech--focused on one mutation that the two variants share, known as N501Y. Scientists believe that this mutation allows the virus to bind more effectively to the body's cells, making it more contagious.
The scientists used blood from 20 people who had received the full two doses of the Pfizer-BioNTech vaccine and found that antibodies it contained neutralized an artificial version of the coronavirus with the N501Y mutations as well as they did variants of the virus that didn't have that mutation.
“A limitation of this study is that the mutation was tested in isolation," said Deborah Dunn-Walters, chairwoman of the British Society for Immunology and Covid-19. "Where evidence, such as structural modelling, indicates that mutations could interact with each other to affect the overall antigen structure they should be tested together.”
However, Prof. Dunn-Walters stressed that vaccines enable the body to create a diverse library of antibodies against the virus, so that the broader immune response induced by the shots should be able to cope with changes to the virus structure.
Pfizer and BioNTech have said their vaccine, which is based on messenger RNA technology, could be tweaked if necessary to respond to different variants.