Scientists recently identified two new strains of SARS-CoV-2 — one of which had been discovered in the United Kingdom and the other in South Africa. A new Pfizer study concludes that its vaccine should be effective against the U.K. variant.
Both new variants, which appear to be more contagious, have mutations in a spike protein called N501Y.
Because most vaccines currently under investigation essentially teach the immune system to respond to the spike proteins, some people have questioned whether the vaccines will be effective against the variants.
The new study, which appears on a preprint server, is a combined effort from Pfizer and scientists at the University of Texas Medical Branch at Galveston.
The researchers analyzed blood samples from 20 people who had received the Pfizer–BioNTech vaccine during previous clinical trials.
They demonstrated that antibodies from vaccine recipients successfully fought off a virus with the N501Y mutation. The study has limitations, though. For instance, the variant first identified in South Africa has an additional mutation known as E484K, which the new study did not address.
Importantly, the study has also not yet been peer-reviewed. Meanwhile, Pfizer’s chief scientific officer, Dr. Philip Dormitzer, acknowledges:
“It was a very reassuring finding that at least this mutation, which was one of the ones people are most concerned about, does not seem to be a problem.”
The authors of the preprint conclude: “The ongoing evolution of SARS-CoV-2 necessitates continuous monitoring of the significance of changes for vaccine coverage. This surveillance is accompanied by preparations for the possibility that a future mutation in SARS-CoV-2 might necessitate a vaccine strain change. Such a vaccine update would be facilitated by the flexibility of mRNA-based vaccine technology.”