In some “good news” for scientists working on a viable vaccine for COVID-19, the latest study has found that the SARS-CoV-2 virus behind the disease shows little variability, despite having at least six strains.
Published in the journal Frontiers in Microbiology, the “most extensive” study ever carried out on SARS-CoV-2 sequencing drew from the analysis of 48,635 coronavirus genomes, which were isolated by researchers in labs all over the world.
The researchers at the University of Bologna in Italy mapped the spread and the mutations of the virus during its journey to all continents.
The findings show that the novel coronavirus presents little variability, approximately seven mutations per sample.
Common influenza has a variability rate that is more than double, the researchers said.
“The SARS-CoV-2 coronavirus is presumably already optimised to affect human beings, and this explains its low evolutionary change,” said Federico Giorgi, a researcher at University of Bologna, and coordinator of the study.
“This means that the treatments we are developing, including a vaccine, might be effective against all the virus strains,” Giorgi said.
The researchers noted that currently there are six strains of the novel coronavirus.
The original one is the L strain, that appeared in Wuhan in December 2019. Its first mutation – the S strain – appeared at the beginning of 2020, while, since mid-January, we have had strains V and G, they said.
To date strain G is the most widespread: it mutated into strains GR and GH at the end of February, according to the researchers.
“Strain G and its related strains GR and GH are by far the most widespread, representing 74 per cent of all gene sequences we analysed,” said Giorgi.
“They present four mutations, two of which are able to change the sequence of the RNA polymerase and Spike proteins of the virus. This characteristic probably facilitates the spread of the virus,” he said.
Besides the six main coronavirus strains, researchers identified some infrequent mutations that, they said, are not worrying at the moment but should be monitored.