Molnupiravir: coding for catastrophe.

Molnupiravir, a wide-spectrum antiviral that is currently in phase 2/3 clinical trials for the treatment of COVID-19, is proposed to inhibit viral replication by a mechanism known as ‘lethal mutagenesis’. Two recently published studies reveal the biochemical and structural bases of how molnupiravir disrupts the fidelity of SARS-CoV-2 genome replication and prevents viral propagation by fostering error accumulation in a process referred to as ‘error catastrophe’.