Coronavirus Mutations: Scientists Puzzle Over Impact

Researchers in the United States and the United Kingdom have identified hundreds of mutations in the virus which causes Covid-19 disease.

Yet none of us has yet decided what this will mean for the spread of the virus in the population and how effective a vaccination might be.

Viruses mutate - it's what they do.

The question is: which of these mutations actually do anything to change the severity of the infectiousness of the disease?

Preliminary research from the US has suggested one particular mutation - D614G - is becoming dominant and could make the disease more infectious.

It hasn't yet been reviewed by other scientists and formally published.

The researchers, from the Los Alamos National Laboratory in New Mexico, have been tracking changes to the "spike" of the virus that gives it its distinctive shape, using a database called the Global Initiative on Sharing All Influenza Data (GISAID).

They noted there seems to be something about this particular mutation that makes it grow more quickly - but the consequences of this are not yet clear.

The research team analyzed UK data from coronavirus patients in Sheffield. Although they found people with that particular mutation of the virus seemed to have a larger amount of the virus in their samples, they didn't find evidence that those people became sicker or stayed in the hospital for longer.

'Mutations not a bad thing'

Another study from University College London (UCL) identified 198 recurring mutations to the virus.

One of its authors, Professor Francois Balloux, said: "Mutations in themselves are not a bad thing and there is nothing to suggest SARS-CoV-2 is mutating faster or slower than expected.

"So far, we cannot say whether SARS-CoV-2 is becoming more or less lethal and contagious."

A study from the University of Glasgow, which also analyzed mutations, said these changes did not amount to different strains of the virus. They concluded that only one type of virus is currently circulating.

Monitoring small changes in the composition of the virus is critical in recognizing the development of vaccines.

Take the 'flu virus: it mutates so rapidly that the shot has to be adjusted every year to deal with the specific strain in circulation.

Drug development

Many of the Covid-19 vaccines currently in development target the distinctive spikes of the virus - the idea is that getting your body to recognize a unique element of the spike will help it to fight off the whole virus. But if that spike is changing, a vaccine developed this way could become less effective.

At the moment this is all theoretical. Scientists don't yet have enough information to say what changes to the virus's genome will mean.

Dr Lucy van Dorp, UCL study co-author, said being able to analyze a large number of virus genomes could be "invaluable to drug development efforts".

However, she told the BBC: "I love genomes, but there is only so much they can say."

Source: BBC