Emerging Coronavirus Variants May Pose Challenges to Vaccines - The New York Times

Laboratory studies of mutations circulating in South Africa suggest they may dodge some of the body’s immune responses.

The steady drumbeat of reports about new variants of the coronavirus — first in Britain, then in South Africa, Brazil and the United States — have brought a new worry: Will vaccines protect against these altered versions of the virus.

People who had survived mild infections with the coronavirus may still be vulnerable to infection with a new variant; and more worryingly, the vaccines may be less effective against the variants.

Existing vaccines will still prevent serious illness, and people should continue getting them, said Dr.

But the vaccines may not prevent people from becoming mildly or asymptomatically infected with the variants, he said.

The studies published on Tuesday night show that the variant identified in South Africa is less susceptible to the antibodies created by natural infection and by vaccines made by Pfizer-BioNTech and Moderna.

(The more contagious variant that has blazed through Britain does not contain these mutations and seems to be susceptible to vaccines.).

Fears that the vaccines would be powerless against new variants intensified at a scientific conference held online on Saturday, when South African scientists reported that in laboratory tests, serum samples from 21 of a group of 44 Covid-19 survivors did not destroy the variant circulating in that country.

The results “strongly, strongly suggest that several mutations that we see in the South Africa variant are going to have a significant effect on the sensitivity of that virus to neutralization,” said Penny Moore, a virologist at the National Institute for Communicable Diseases in South Africa who led the study.

Nussenzweig and his colleagues tested samples from 14 people who had received the Moderna vaccine and six people who had received the Pfizer-BioNTech vaccine.

Once enough people get vaccinated, it will become very difficult for the coronavirus to find vulnerable people to infect.

But the clinical trials that delivered these results were not designed to determine whether vaccinated people could still spread the coronavirus without developing symptoms.

We know that people who are naturally infected by the coronavirus can spread it while they’re not experiencing any cough or other symptoms.

Tens of thousands of people have already received the vaccines, and none of them have reported any serious health problems.

The researchers saw a slight decrease in antibody activity directed against engineered viruses with three of the key mutations in the variant identified in South Africa.

In most people, infection with the coronavirus leads to a strong immune response; the vaccines seem to induce an even more powerful response.

Two doses of the vaccines from Pfizer and Moderna, at least, produce neutralizing antibodies at levels that are higher than those acquired through natural infection.

Vaccine trials being conducted in South Africa by Novavax and Johnson & Johnson will provide more real-world data on how the vaccines perform against the new variant there.

The mutations in the variant circulating in South Africa, called B.1.351, have independently emerged more than once, and all together, suggesting that they work in concert to benefit the virus.