Scientists reported this week that the virus may have undergone modifications due to an anti-Covid medication that is widely used worldwide, but there is no proof that these alterations has produced more lethal versions of the virus.

Merck’s antiviral pill molnupiravir became one of the first treatments used during the pandemic to keep people who were more likely to get Covid from getting worse.

The drug is taken by mouth over the course of five days. It mostly works by changing the virus in ways that make it weaker and eventually kill it.

A new study from the UK, on the other hand, says that molnupiravir “can result in the development of significantly mutated viruses that stays viable,” as lead author Theo Sanderson informed AFP.

Sanderson, a biologist at the Francis Crick Institute in London, emphasized that there is no indication that “molnupiravir has thus far produced more transmissible or even more virulent viruses.”

He also said that none of the versions that have spread around the world were caused by the drug.

He did say, though, that “it is hard to say if molnupiravir treatment might cause a new widely circulated version that people aren’t already immune to.”

Signature of mutation

The researchers went through databases of over 15 million genome sequences of SARS-CoV-2, a virus responsible for the Covid illness, for the research, that was published in the journal Nature.

Researchers used this information to see how the virus changed during the pandemic. They found a certain “mutational signature” in patients that they think is connected to molnupiravir.

The study found that there was a big rise in patients with this mutational marker in 2022 when the drug was given to a lot of people.

People in the US, Australia, the UK, and Japan, where the medication was widely given, were more likely to have this marker.

But it happened less often in places like Canada and France where it wasn’t allowed.

Merck disagreed with the study and said the researchers had only used “circumstantial associations” to figure out when and where the sequences had been taken.

“The authors think these mutations were linked to viral spread from molnupiravir-treated patients, but there is no proof of that transmission,” Merck claimed in a statement provided to AFP.

This assertion was refuted by Sanderson, who stated that the researchers “have proven that molnupiravir is the mutational signature’s driver using multiple independent lines of evidence.”

This includes an independent examination of treatment data from England, which discovered that individuals who had taken molnupiravir accounted for almost 30% of the mutation occurrences containing the signature.

The study did find that in 2022, only 0.04% of people in England were given the drug.

He said that these kinds of changes would not happen with other anti-Covid drugs because they do not work the same way.