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Syringes containing the Pfizer-BioNTech COVID-19 vaccine sit in a tray in a vaccination room at St. Joseph Hospital in Orange, Calif., Thursday, Jan. 7, 2021.Jae C. Hong/The Associated Press

Pfizer Inc and BioNTech’s COVID-19 vaccine appears able to protect against a key mutation in the highly transmissible new variants of the coronavirus discovered in Britain and South Africa, according to a laboratory study conducted by the U.S. drugmaker.

The study by Pfizer and scientists from the University of Texas Medical Branch, which has not yet been peer-reviewed, indicated the vaccine was effective in neutralizing virus with the so-called N501Y mutation of the spike protein.

The mutation is linked to greater transmissibility and there had been concerns it could also make the virus escape antibody neutralization elicited by the vaccine, said Phil Dormitzer, one of Pfizer’s top viral vaccine scientists.

The first results of tests on the variants offer some hope as Britain and other countries try to tame the more infectious variants which authorities believe are driving a surge in infections that could overwhelm health care systems.

The study was conducted on blood taken from people who had been given the vaccine. Its findings are limited because it does not look at the full set of mutations found in either of the new variants of the rapidly spreading virus.

Dormitzer said it was encouraging that the vaccine appears effective against the mutation, as well as 15 other mutations the company has previously tested against.

“So we’ve now tested 16 different mutations, and none of them have really had any significant impact. That’s the good news,” he said. “That doesn’t mean that the 17th won’t.”

Dormitzer said another mutation found in the South African variant, called the E484K mutation, was also concerning.


The U.S. researchers plan to run similar tests to see whether the vaccine protects against other mutations found in the British and South African variants and hope to have data within weeks.

The variants are said by scientists to be more transmissible than previously dominant ones, but they are not thought to cause more serious illness.

Independent experts gave a cautious welcome to the Pfizer study findings, but said the situation needs constant vigilance.

Paul Hunter, a professor in medicine at Britain’s University of East Anglia, said “the jury is still out on the impact of the South African variant on vaccine efficacy.”

Deborah Dunn-Walters, a professor of immunology at Surrey University in Britain, said it was “reassuring” that Pfizer is closely monitoring variants.

Ongoing testing will be needed, experts said, to allay concerns about whether vaccines being given to millions of people in the fight against the pandemic will protect them as the virus mutates. COVID-19 has killed more than 1.8 million people worldwide.

“The evidence is not conclusive but there is a lot to indicate that the existing MRNA vaccines do cover the new variants. That is the good news,” Andreas Bergthaler, principal investigator at the Research Center for Molecular Medicine of the Austrian Academy of Sciences in Vienna.


AstraZeneca, Moderna and CureVac are also testing whether their shots will protect against the fast-spreading coronavirus variants. They have said they expect them to be effective, but have not said when study results will be published.

A senior British lawmaker expressed concerns in an interview on Friday that COVID-19 vaccines might not work properly against the South African variant. He was not responding to questions about Friday’s data.

The Pfizer/BioNTech COVID-19 vaccine and the one from Moderna Inc, which use synthetic messenger RNA technology, can be quickly adapted to address new mutations in the coronavirus if necessary. Scientists have suggested the changes could be made in as little as six weeks.

The variant is not the first of the pandemic to emerge and Eleanor Riley, a professor of immunology and infectious disease at the Edinburgh University, said similar studies would need to be repeated as new mutations appear. “It may be necessary to tweak the vaccine over time,” she said.

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