The findings build on a study published in the journal Infection, Genetics and Evolution earlier this month which characterised patterns of diversity emerging in the genome of the SARS-CoV-2 virus that causes COVID-19.
“As a growing number of mutations have been documented, scientists are rapidly trying to find out if any of them could make the virus more infectious or deadly, as it’s vital to understand such changes as early as possible,” said Professor Francois Balloux from University College London (UCL) in the UK.
“We employed a novel technique to determine whether viruses with the new mutation are actually transmitted at a higher rate, and found that none of the candidate mutations appear to be benefiting the virus,” said Balloux, lead author of the yet-to-be peer-reviewed study published as a pre-print on bioRxiv.
Coronaviruses, like other RNA viruses, can develop mutations in three different ways: by mistake from copying errors during viral replication, through interactions with other viruses infecting the same cell, or they can be induced by RNA modification systems which are part of host immunity, the researchers explained.
Most mutations are neutral, while others are advantageous or detrimental to the virus, they said.
The scientists added that all these types of mutations can become more common as they get passed down to descendant viruses.
The team from UCL, and the University of Oxford in the UK, has so far identified 6,822 mutations in SARS-CoV-2 across the global dataset.
The researchers said for 273 of the mutations, there is strong evidence that they have occurred repeatedly and independently.