Coronavirus: Mutant virus ‘an urgent concern’ scientists warn

About half the COVID-19 cases in Australia studied by the CSIRO have been found to be a mutant strain that may be more contagious.

A scanning electron microscope image of SARS-CoV-2 emerging from the surface of cells cultured in the lab. Picture: AFP

About half the COVID-19 cases in Australia studied by the CSIRO have been found to be a mutant strain of the virus that may be more contagious.

Labelled an “urgent concern’’ by international researchers, about two-thirds of cases in hard-hit countries have been found to have the mutation.

NSW and Queensland appear to have dodged the worst of the mutation; it has been identified in only about one-third of cases in these states.

However, Victoria and Western Australia are in line with a global trend of having two-thirds of cases with the mutation.

The Weekend Australian can reveal the CSIRO has for weeks been monitoring the spread of the new strain around the nation. The CSIRO identified the strain even before a team of international ­scientists described the mutation in a major scientific paper.

Scientists led by a team at the Los Alamos National Laboratory in the US this week published a pre-print paper that documented 14 mutations in the coronavirus spike protein that attaches itself to human cells, identifying one of the spike mutations — known as D614G — as being of “urgent ­concern”. The scientists said the ­mutation spike D614G began spreading in Europe in early February, and had quickly become the dominant form of SARS-CoV-2 when it was introduced to new ­regions.

The team, which included scientists from Duke University in North Carolina and the University of Sheffield in England, said the revelation may be concerning for vaccine development, because if the virus is mutating readily, any vaccine that is developed may not be effective for what the current dominant strain of the virus is.

The CSIRO has been at the forefront of analysing the genome of the SARS-CoV-2 virus that causes COVID-19, and has already undertaken detailed work in monitoring mutations of the virus and the spread of new strains state-by-state. Scientists at the CSIRO published a peer-reviewed paper on April 19 that analysed the first 181 published genomic ­sequences of the SARS-CoV-2 virus.

CSIRO Dangerous Pathogens team leader Seshadri Vasan said the D614G mutation was not ­observed in those sequences. But the CSIRO’s head of bioinformatics, Denis Bauer, said since the paper was published, the CSIRO had been tracking the new coronavirus strain.

Dr Bauer’s team has surveyed hundreds of isolates of the virus from Australia.

“After publishing our paper, we have been monitoring whether Australia will be affected by the D614G change in the spike protein,” Dr Bauer said.

“In Australia it seems now to be less frequent than the world average, appearing in only 50 per cent of the surveyed ­sequences.

“This mutation is present in roughly two-thirds of all global strains but only represents half of all Australian strains.

“NSW and Queensland show the lowest rate of the mutation, while Victoria and Western Australia more closely resemble the international distribution.

“NT is split down the middle, while there was no data for Tasmania or South Australia.”

The new strain of the virus was seen in one-third of viral isolates surveyed by the CSIRO in NSW and Queensland.

The new strain made up two-thirds of cases surveyed in Victoria and Western ­Australia, and half of all viral ­isolates in the Northern Territory.

Despite the prevalence of the apparent new strain of the coronavirus in all states, the CSIRO does not believe it is necessarily more contagious, as speculated by international scientists.

Professor Vasan said laboratory studies would be necessary to confirm whether that was the case.

“The emergence of strains which replicate efficiently and cause associated pathology is not unexpected,” Professor Vasan said.

“However, susceptible people will also become less common over time, so we will observe selection of strains producing less severe disease but having a prolonged, lower-level infection.

“This is a well-known effect, called the ‘survival of the flattest’. The environment is a major evolutionary driver in these cases.”

Professor Vasan downplayed the significance of the discovery of the virus mutation on the development of an effective vaccine.

“Based on what we know at this point, we do not believe that this poses serious concerns about vaccine development similar to seasonal influenza, where we need to tweak the vaccine each year for the northern and southern hemispheres,” he said.

“However, as many vaccines for COVID-19 target the spike region, so we will keep a close watch on this and other mutations.”