Use of antiviral may be fuelling evolution of Covid, scientists say

There is no evidence molnupiravir has produced more dangerous Covid variants, but experts say the mutations increase the genetic diversity of the virus in the wild. Photograph: Merck/AFP/Getty

An antiviral drug used to treat patients with Covid-19 may be causing mutations in the virus and fuelling the evolution of new variants, scientists have said.

Molnupiravir, which is also sold under the brand name Lagevrio, is designed to mutate coronavirus to destruction, but researchers found evidence that the virus can sometimes survive the treatment, leading to mutated versions that occasionally spread to other people.