Molnupiravir, the oral pill for COVID-19, may actually be driving the emergence of new, potentially harmful, variants of the virus, according to a Wellcome Trust-funded study at the pre-print stage. The news may come as a blow for Merck, the drug’s manufacturer, which reported massive revenues over the last year, and for the US government, which heavily subsidised the drug’s production and distribution. It will be vindication – albeit unwanted – for those who warned the drug was dangerous and should not be given emergency-use authorization by the FDA.
Merck’s antiviral drug works by causing specific kinds of mutation in the virus, the theory being that the virus will literally “mutate itself to death”, as Dr Harvey Risch, an emeritus professor from the Yale School of Public Health, explained.
Problems could potentially arise if patients treated with the drug do not fully clear an infection, and a drug-mutated strain escapes and infects other people. That this is now happening – if the new paper is correct – is “not a surprise”, Risch adds.
A team of researchers from the US and UK used global databases of SARS-COV-2 sequences to search for mutations that were characteristic of the changes Molnupiravir makes to the viral genome. They found noticeable increases in such changes in the database beginning from when the drug was first marketed. Importantly, the increases took place in those countries where the drug was used.