Pfizer and BioNTech announced on Friday that their Covid vaccine is effective against one of the mutations present in the new infectious variants identified in the UK and South Africa.
Independent experts said the findings were good news, but warned that each of these variants of the coronavirus had several other potentially dangerous mutations that had not yet been investigated. So it is possible that one of these mutations will affect how well the vaccine works.
“This is the first step in the right direction,” said Dr. John Brooks, chief medical officer of the Covid-1
The new version, known as B.1.1.7, first raised concerns in December, when British researchers realized it was rapidly becoming more common among people with Covid-19. It has since appeared in 45 countries.
Subsequent research has confirmed that it has the ability to spread more easily from person to person. On Friday, Public Health England published a new study on B.1.1.7, in which researchers estimated that the variant was 30 to 50 percent more susceptible than other forms of the virus.
The viral line leading to B.1.1.7 has accumulated 23 mutations. Of particular importance to scientists are eight mutations that affect a gene in a protein called a spike on the surface of coronaviruses. This is because viruses use spike protein to trap human cells. It is possible that one or more of them help B.1.1.7 to invade the cells more successfully.
One of these mutations, known as N501Y, is particularly worrying. Experiments have shown that it allows the virus to bind to cells more closely. And it has appeared in other genera of the coronavirus, including a variant identified in South Africa in December. This variant, called B.1.351, is spreading rapidly in the country and has so far spread to a dozen other countries.
In the new study, which was published online Thursday and has not yet undergone a formal scientific review, researchers at the University of Texas Medical Branch conducted an experiment to test whether the Pfizer-BioNTech vaccine works against viruses with the N501Y mutation. They found that in the cells in the laboratory, the mutant virus could not infect human cells mixed with antibodies from vaccinated people. The antibodies bind to the coronaviruses and block them from attaching to the cells. Despite the N501Y mutation, the experiment showed that the antibodies generated by the vaccine were still able to attach to the viruses.
“This shows that the key mutation N501Y, which is found in emerging variants for the United Kingdom and South Africa, does not create resistance to the immune responses induced by the Pfizer-BioNTech vaccine,” the companies said in a news release.