Pharmaceutical giant Merck’s antiviral pill molnupiravir was one of the earliest treatments rolled out during the pandemic to prevent Covid becoming more severe in vulnerable people.
The drug, which is taken orally over a five-day course, works mainly by creating mutations in the virus with the goal of weakening and killing it. However, a new UK-led study has shown that molnupiravir “can give rise to significantly mutated viruses which remain viable,” lead author Theo Sanderson said.
Sanderson, a geneticist at London’s Francis Crick Institute, emphasised that there is no evidence that “molnupiravir has to date created more transmissible or more virulent viruses.” None of the variants that have swept the world were due to the drug, he added. But “it is very difficult to predict whether molnupiravir treatment could potentially lead to a new widely circulating variant which people don’t have prior immunity to,” he added.