A drug used to deal with COVID-19 could have led to mutations within the virus, a research mentioned Monday.
Pharmaceutical big Merck’s antiviral capsule molnupiravir was one of many earliest remedies rolled out in the course of the pandemic to stop COVID-19 from changing into extra extreme in weak folks.
The drug, which is taken orally over a five-day course, works primarily by creating mutations within the virus with the purpose of weakening and killing it.
Nevertheless, a brand new U.Okay.-led research has proven that molnupiravir “can provide rise to considerably mutated viruses which stay viable,” lead writer Theo Sanderson advised Agence France-Presse (AFP).
Sanderson, a geneticist at London’s Francis Crick Institute, emphasised that there is no such thing as a proof that “molnupiravir has to this point created extra transmissible or extra virulent viruses.”
Not one of the variants which have swept the world have been because of the drug, he added.
However “it is extremely troublesome to foretell whether or not molnupiravir remedy might doubtlessly result in a brand new extensively circulating variant which individuals do not have prior immunity to,” he added.
For the research, which was revealed within the journal Nature, the researchers sifted via databases of greater than 15 million genome sequences of SARS-CoV-2, the virus that causes the Covid illness.
The researchers used this knowledge to trace adjustments in how the virus mutated in the course of the pandemic, discovering indicators of a specific “mutational signature” in sufferers they consider is linked to molnupiravir.
In 2022, because the drug was prescribed in large numbers, there was a major improve in sufferers who had this mutational signature, the research discovered.
This signature was extra generally present in international locations the place the drug was extensively prescribed, akin to the US, U.Okay., Australia and Japan.
However in international locations the place it was not permitted, together with Canada and France, it was rarer.
Merck refuted the research, saying the researchers had relied on “circumstantial associations” between the place and when the sequences have been taken.
“The authors assume these mutations have been related to viral unfold from molnupiravir-treated sufferers with out documented proof of that transmission,” Merck mentioned in an announcement despatched to AFP.
Sanderson rebuffed this declare, saying the researchers had used “a number of impartial strains of proof to determine with confidence that molnupiravir drives this mutational signature.”
That included a separate evaluation of remedy knowledge in England, which discovered that greater than 30% of mutation occasions involving the signature have been in individuals who had taken molnupiravir.
Nevertheless, simply 0.04% of individuals in England have been prescribed the drug in 2022, the research mentioned.
Different anti-Covid medicine don’t work in the identical method, so wouldn’t trigger these sorts of mutations, Sanderson mentioned.
Specialists not concerned within the research appeared to facet with the British researchers.
Stephen Griffin, a virologist on the U.Okay.’s College of Leeds, mentioned it was an “extremely necessary, well-conducted piece of analysis.”
Jonathan Ball, a virologist on the College of Nottingham, mentioned the analysis confirmed a “sturdy hyperlink” between molnupiravir and the occasional, restricted unfold of extremely mutated genomes.
“What is not clear is that if any of the transmitted viruses contained mutations which might change how they’d behave – for instance, in the event that they have been kind of transmissible, extra pathogenic or much less vulnerable to our immunity,” he added.
The consultants emphasised that molnupiravir shouldn’t be harmful to people who find themselves at present taking the drug.
In addition they didn’t name for the drug to be deserted altogether.
Molnupiravir is already being utilized by itself “much less and fewer” as its effectiveness had waned towards vaccinated people who find themselves not in danger, Griffin mentioned.
Whereas the present analysis may counsel that molnupiravir ought to not be prescribed by itself, “it should not be discarded and will nonetheless be priceless if we have been to make use of it in drug mixtures,” he added.
Gross sales of molnupiravir, offered underneath the model title Lagevrio, topped $20 billion final yr. Nevertheless, gross sales fell 82% within the second quarter of 2023 in comparison with the identical interval final yr, in keeping with Merck.