Daily briefing: COVID-19 drug might be spurring new variants

Signature of molnupiravir might be in SARS-CoV-2 genomic sequence. Plus, the everyday chemicals that make us fatter and codebreakers decrypt the long-lost letters of Mary, Queen of Scots.

COVID drug might drive viral mutations

Molnupiravir, a drug widely used to treat COVID-19, might be spurring the evolution of new SARS-CoV-2 variants. The drug works by peppering the coronavirus’s genome with mutations, which add up to make SARS-CoV-2 worse at replicating. But scientists have raised the possibility that, in rare cases, molnupiravir treatment might not entirely eliminate SARS-CoV-2, allowing some individuals who have taken the drug to continue to transmit the virus. Now, a preprint study (which is not yet peer reviewed) of more than 13 million SARS-CoV-2 sequences has uncovered sequences that bear molnupiravir’s fingerprints. Quantitative bioscientist Rustem Ismagilov says the study underscores the need to quickly assess the risk of continued use of the drug. “If we are playing Russian roulette, we’d better know our odds.”

Nature | 5 min read

Reference: medRxiv preprint (not peer-reviewed)