Scientists have raised concerns that the antiviral drug Molnupiravir may be causing mutations in the Covid-19 virus, leading to the evolution of new variants. The drug is designed to mutate the virus to destruction, but researchers have found evidence that the virus can sometimes survive the treatment, resulting in mutated versions that can spread to other people. While there is no evidence that Molnupiravir has produced more dangerous variants of Covid-19, the mutations have increased the genetic diversity of the virus in the wild and provided more options for future evolution.

The findings of the study have important implications for the assessment of the risks and benefits of Molnupiravir and other similar drugs in development. Global databases containing more than 15 million Covid genomes were examined, and hallmark mutations were found in viruses from 2022, after Molnupiravir was introduced. The proportion of specific mutations at certain regions of the genetic code increased when the drug mutated the virus’s RNA. These hallmark mutations were more common in countries that used the most Molnupiravir, such as the UK, Australia, the US, and Japan. The mutations were also more common in Covid virus samples taken from older patients who were more likely to be treated with the drug. The study also found a high number of viral samples in England with the signature mutations of Molnupiravir, suggesting a connection between the drug and the mutations.

However, the implications of the mutations are still unclear, and there are no widely circulating variants that are specifically due to Molnupiravir. Most mutations in the virus are expected to weaken it rather than make it more dangerous. Scientists are investigating if the drug-induced mutations could explain the rise in virus levels observed in the Oxford University’s Panoramic trial, which is studying the effectiveness of Covid antivirals. The trial found that Molnupiravir did not reduce the risk of hospitalization or death among vaccinated, high-risk patients facing the Omicron variant, but it did speed up recovery time. Experts suggest that Molnupiravir may still be valuable if used in combination with other drugs and should not be discarded entirely.

The manufacturer of Molnupiravir, MSD, has stated that the drug impairs viral replication and reduces shedding, thus lowering the risk of transmission. The company disagrees with the authors of the study, stating that there is no documented evidence of viral spread from Molnupiravir-treated patients and that the conclusions drawn are based on circumstantial associations.

In conclusion, concerns have been raised about the potential for Molnupiravir to cause mutations in the Covid-19 virus, leading to the evolution of new variants. While the implications of these mutations are still unclear, scientists are investigating the connection between the drug and the rise in virus levels observed in the Panoramic trial. Despite the concerns, experts suggest that Molnupiravir may still have value in combination with other drugs, and the manufacturer maintains that the drug reduces the risk of transmission. Further research is needed to fully understand the effects of Molnupiravir on the evolution of the Covid-19 virus.