Pfizer Covid-19 vaccine appears to work against mutation of new coronavirus strains, study finds

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The two strains share a mutation known as N501Y, which scientists worry could allow the virus to evade immune protection from a vaccine.
In research posted online on Thursday, scientists found that antibodies from people who received the Pfizer / BioNTech vaccine showed “no reduction in neutralizing activity” compared to a version of the virus that carries the N501Y mutation, which they created. o in the lab.

To do this, the researchers tested the virus against the blood of 20 people who received two doses of the vaccine as part of a clinical trial.

The N501Y mutation is located in the coronavirus’s peak protein – the same structure targeted by vaccines. The virus uses this protein to enter the cells it attacks.

Here's how mutations can help the coronavirus escape vaccines

This special mutation appears to help the virus attach to human cells, which may partly explain why these new strains appear to be more transmissible. But scientists have worried that one of the many mutations in both strains could make the virus less susceptible to vaccines or treatments.

The study – conducted by researchers at Pfizer and the University of Texas Medical Branch – does not test the full range of these mutations, nor has it been evaluated by colleagues.

While waiting for viruses to mutate – often in neutral or even harmful ways – the experts say that the whole is not just the sum of the parts: some mutations are known to interact with each other, occasionally changing the shape or function of structures such as spike protein.

“One limitation of this study is that the mutation was tested in isolation,” said Deborah Dunn-Walters, chair of the British Society for Immunology on Covid-19 and immunology, in a statement. She noted that mutations that can have a compound effect “should be tested together”.

Because humans usually produce several types of antibodies against a virus, experts say such a mutation is unlikely to make the virus completely resistant to the vaccine. However, experts are not so sure that the new strains will not have an impact at all.

“We will need to see effective protection against new variants in participants in clinical trials that are still ongoing to ensure that the vaccine is just as effective,” said Alexander Edwards, an associate professor of biomedical technology at the University of Reading School of Pharmacy in Britain said in a statement. Neither Edwards nor Dunn-Walters were involved in the new research.

If a virus is more transmissible or less susceptible to a vaccine, experts say this could also raise the bar for the number of people who should be vaccinated to gain immunity from the herd.

In a statement last month, Pfizer said it had performed similar tests on “multiple mutant strains. So far, we have found a consistent coverage of all the strains tested “.

It will be important to continue monitoring the significance of changes to vaccine coverage, the researchers wrote in the new paper.

This is due to “the possibility that a future mutation … may require a change in the vaccine strain”. Both Pfizer and Moderna vaccines use genetic technology that would allow the vaccines to adapt quickly to account for mutations, they said.

In a statement Friday, BioNTech said Pfizer and Pfizer are “encouraged by these early findings from the in vitro study,” but stressed that “additional data are needed” to look at how effective the vaccine is in preventing disease. new variants.

CNN’s Jacqueline Howard and Maggie Fox contributed to this report.

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