New Study Suggests Antiviral Molnupiravir Could Potentially Lead to New Variants of Coronavirus
A team of scientists has recently published a study in the journal Nature, stating that the antiviral drug molnupiravir could potentially lead to the evolution of new variants of the coronavirus. While the drug is indicated for the treatment of Covid in adults at greater risk of severe forms of the disease, researchers have found that its use can lead to mutated versions of the virus that can occasionally be transmitted to other people.
Molnupiravir works by inducing mutations in the virus’s genome, thus preventing its replication and allowing for the elimination of the infection. However, the study revealed that in some cases, mutated forms of the virus can survive treatment with the drug. It should be noted that there is currently no evidence suggesting that molnupiravir has produced more dangerous variants of the virus.
One of the key findings that support the possibility of molnupiravir producing viable mutated forms of the virus comes from the analysis of global databases, GISAID and INSDC, which contain over 15 million sequenced genomes. Researchers discovered characteristic mutations, characterized by a high proportion of GA and CT mutations, starting from 2022 when molnupiravir was introduced.
Dr. Theo Sanderson, the lead author of the study and a postdoctoral researcher at the Francis Crick Institute in London, explained that molnupiravir induces mutations due to its chemistry. Its structure is similar to an RNA base and can exist in two forms, one that resembles cytosine and binds to guanine and another form that binds to adenine. This means that it mainly causes GA and CT mutations.
Further analysis revealed that the characteristic mutations were more common in countries where molnupiravir is widely used, such as the United Kingdom, Australia, the United States, and Japan. Additionally, these mutations were more prevalent in viral samples from older patients who were more likely to be treated with the drug.
To strengthen the evidence linking molnupiravir to these mutations, researchers compared viral samples collected in England with data from the United Kingdom Health Security Agency (UKHSA) regarding patients who were treated with the drug. The number of sequences with a high proportion of GAs belonging to patients treated with molnupiravir was significantly higher than expected by chance.
While the risk associated with the emergence of these mutations is still not fully understood, it is important to note that none of the new variants of concern have been linked to the use of molnupiravir so far. The findings from this study will be valuable for modeling studies that aim to assess the risk and regulators who need to evaluate the potential risks and benefits of treatments like molnupiravir.