The Pfizer/BioNTech COVID-19 vaccine appears to protect against a mutation that has been found in two highly contagious variants of coronavirus which have spread from the UK and South Africa.
New research suggests that the N501Y mutation, found in the variants that are causing global concern, can be fought off by the antibodies provided by the Pfizer vaccine.
N501Y is a slight alteration on one spot of the spike protein that coats the virus - which is believed to be the reason they can spread so easily.
Most of the vaccines being rolled out around the world train the body to recognise that spike protein and fight it.
Pfizer worked with researchers from the University of Texas Medical Branch in Galveston for laboratory tests to see if the mutation affected its vaccine's ability to do so.
They used blood samples from 20 people who received the vaccine, made by Pfizer and its German partner BioNTech, during a large study of the shots.
Antibodies from those vaccine recipients successfully fought off the virus in lab dishes, according to the study posted late on Thursday on an online site for researchers.
The study is however just preliminary and has not yet been reviewed.
Chief scientific officer at Pfizer, Dr Philip Dormitzer, said “it was a very reassuring finding”.
A second mutation on the South Africa variant, called E484K, was however not part of the study, which looked at 15 additional possible mutations.
Viruses constantly undergo minor changes as they spread from person to person.
Scientists have used these slight modifications to track how the coronavirus has moved around the globe since it was first detected in China a year ago.
British scientists have said the variant found in the UK - which has become the dominant type in parts of England - still seemed to be susceptible to vaccines.
Dormitzer said E484K was next on the list to be looked at.
Dr. Anthony Fauci, the top US infectious disease expert, recently said vaccines are designed to recognize multiple parts of the spike protein, making it unlikely a single mutation could be enough to block them. But scientists around the world are conducting research with different vaccines to find out.
Dormitzer said if the virus eventually mutates enough that the vaccine needs adjusting – much like flu shots are adjusted most years – that tweaking the recipe wouldn’t be difficult for his company's shot and similar ones.
The vaccine is made with a piece of the virus's genetic code, simple to switch, although it’s not clear what kind of additional testing regulators would require to make such a change.
Dormitzer said this was only the beginning “of ongoing monitoring of virus changes to see if any of them might impact on vaccine coverage.”