Emerging coronavirus variants may pose challenges to vaccines

Emerging coronavirus variants may pose challenges to vaccines

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?

The answer so far is yes, several experts said in interviews. But two small new studies, posted online Tuesday night, suggest that some variants may pose unexpected challenges to the immune system, even in those who have been vaccinated — a development that most scientists had not anticipated seeing for months, even years.

The findings result from laboratory experiments with blood samples from groups of patients, not observations of the virus spreading in the real world. The studies have not yet been peer-reviewed.

But experts who reviewed the papers agreed that the findings raised two disturbing possibilities. 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.