Molnupiravir: A Warning of Unexpected Mutations in Global SARS-CoV-2 Genomes

A study published in Nature reveals that the antiviral medication molnupiravir, widely used against SARS-CoV-2, induces mutations in the virus genome during replication. The study finds evidence of molnupiravir mutagenesis in SARS-CoV-2 sequencing databases, with a specific mutational signature characterized by a high proportion of G-to-A and C-to-T mutations. These mutations appear predominantly in sequences from 2022, after the introduction of molnupiravir treatment, and in countries and age-groups with widespread usage of the drug. The study confirms a direct association between these mutations and the use of molnupiravir, raising concerns about the potential for onward transmission of molnupiravir-mutated viruses.