An antiviral drug used to treat Covid-19 infections has been linked to mutations of the coronavirus that are suspected to then be passed on to other people, researchers say.
Scientists mapped COVID-19 mutations over time to see how and when the virus evolved, and spotted unusual “mutational events” associated with patients who had taken the drug molnupiravir.
It was one of the first antivirals to be made available to treat COVID-19 during the pandemic and works by inducing mutations in the virus’s genome, which essentially prevent the virus from multiplying, reducing the viral load. This then helps the body’s immune system control the infection.
The World Health Organization (WHO) recommended molnupiravir for the treatment of patients at high risk of hospitalization in March 2022, making it the first oral antiviral drug in its guidance on treating the infection. https://www.euronews.com/next/2022/03/03/who-recommends-covid-antiviral-pill-for-the-first-time-to-treat-those-at-high-risk
Researchers from the UK’s Francis Crick Institute, the University of Cambridge, Imperial College London, the University of Liverpool, the University of Cape Town and the UK Health Security Agency (UKHSA) examined global sequencing databases of the COVID-19 virus, analyzing a “family tree” of 15 million sequences.
This helped them trace the evolutionary history of the virus, pinpointing when mutations occurred. The researchers say that while viruses continually mutate, they identified “mutational events” that were different from normal mutation patterns and were “strongly associated with individuals who had taken molnupiravir.”
Publishing their findings in the journal Nature, the researchers said the mutations were found to increase in 2022, at a time that coincides with the introduction of molnupiravir. They also found that the mutations were more likely in older patients, who were more likely to be prescribed the drug as they were deemed more at risk of hospitalization.
“Molnupiravir is one of several drugs used to fight COVID-19. It belongs to a class of drugs that can cause the virus to mutate in such a way that it is fatally weakened,” said Christopher Ruis of the University of Cambridge’s Department of Medicine.
“But what we have found is that in some patients this process does not kill all viruses and some mutated viruses can spread. This is important to take into consideration when evaluating the overall benefits and risks of molnupiravir and similar drugs.”
The researchers found that at least 30% of “mutation events” in England involved the use of molnupiravir. They saw small clusters of mutations that suggested other patients had been infected by the mutated virus. However, no variants of concern are currently linked to this signature, they added.
“COVID-19 is still having major effects on human health and some people have difficulty eradicating the virus, so it is important to develop drugs that aim to reduce the duration of the infection,” said Theo Sanderson, lead author and post-researcher. doctorate from the Francis Crick Institute.
“But our evidence shows that a specific antiviral drug, molnupiravir, also causes new mutations, increasing genetic diversity in the surviving viral population.”
He said the findings are useful for the ongoing evaluation of molnupiravir and that the development of new drugs should take into account the possibility that the mutations are caused by antivirals.
“Our work demonstrates that the unprecedented size of post-pandemic sequence datasets, built collaboratively by thousands of researchers and healthcare workers around the world, creates enormous power to reveal information about the evolution of the virus that would not be possible. possible from the analysis of data from any single country,” he added.