A team of scientists has issued a warning after a study found that a popular antiviral drug used to treat Covid is triggering mutations of the virus.
The drug, molnupiravir, is driving an unintended pattern of mutations in the SARS-CoV-2 virus that is increasing its genetic diversity and causing it to spread, the scientists warn.
This is the warning of an international team of researchers who studied some 15 million SARS-CoV-2 sequences.
The study sought to map out exactly how the coronavirus has mutated over time.
While viruses do naturally mutate, the analysis revealed mutational events that looked very different from the regular pattern of change.
Nearly a third of these unusual shifts were associated with people who had taken the antiviral molnupiravir.
This drug — manufactured by pharmaceutical giant Merck and Ridgeback Biotherapeutics — works by inducing mutations in the viral genome during replication.
Many of these mutations either damage or kill the virus, helping to reduce the body’s viral load.
However, the team found that some of the changes caused by molnupiravir aren’t having the intended effect — and are causing enduring mutations instead.
The analysis revealed small clusters of these mutations, suggesting that they are being