Coronavirus: Variant mutation lets it copy itself more efficiently

Senior health adviser Dr. Anthony Fauci has warned that a new mutation of coronavirus could spread easily across America. 

It comes as infections soar across eight states, with more than 55,000 new COVID-19 cases on Thursday and 671 deaths, bringing the confirmed total to 2.74 million cases and 128,742 deaths. 

A small change to a variant of the novel coronavirus has helped it better copy itself but not make it more deadly, a new study suggests.

Researchers found there were two strains of the virus circulating when it reached the US: the original D614 and a mutation, G614. 

This mutation is not a deadlier version of the coronavirus but it does help the virus copy itself better, which results in a higher viral load in patients. 

Senior health adviser Dr. Anthony Fauci (pictured) has warned that a new mutation of coronavirus could spread easily across America. This mutation is not a deadlier version of the coronavirus but it does help the virus copy itself better, which results in a higher viral load in patients

Researchers found the most dominant strain of the virus by mid-March was a mutation of the original variant called G614 (right, in blue), not the original virus D614 (left, in green)

Researchers found the most dominant strain of the virus by mid-March was a mutation of the original variant called G614 (right, in blue), not the original virus D614 (left, in green)

Dr Erica Ollmann Saphire, a professor of at the La Jolla Institute of Immunology in California, says viruses often mutate to ‘escape’ antibodies created by our immune systems.

This phenomenon of viruses making enough changes to ‘drift’ away from the original virus is known as antigenic drift.

It’s one reason why new flu shots are needed every fall, because the dominant strain is often so different from the one the year before.  

Health experts say coronavirus mutates at a slower rate than several other respiratory viruses, particularly the the flu. 

The lab-based research, published in the journal Cell, suggests this current mutation is more transmissible between people in the real world compared to the previous iteration, but this hasn’t yet been proven. 

‘I think the data is showing that there is a single mutation that actually makes the virus be able to replicate better, and maybe have high viral loads,’ Anthony Fauci, the United States’s top infectious disease specialist, who wasn’t involved in the research, commented to Journal of the American Medical Association.

‘We don’t have a connection to whether an individual does worse with this or not. It just seems that the virus replicates better and may be more transmissible, but this is still at the stage of trying to confirm that,’ he added. 

‘But some very good viral phylogeneticists are working on that right now, and it does look like a particular mutation may make the virus more transmissible.’ 

For the study, the team tracked the spread of both the G and D viruses. 

The G strain is not a deadlier version, but it allows the virus to copy itself more easily and create higher viral loads in patients. Pictured: Paula Johnson, a nurse, administers a deep suction tube into the lungs of a coronavirus patient, in the ICU of Roseland Community Hospital in Chicago, Illinois, April 22

The G strain is not a deadlier version, but it allows the virus to copy itself more easily and create higher viral loads in patients. Pictured: Paula Johnson, a nurse, administers a deep suction tube into the lungs of a coronavirus patient, in the ICU of Roseland Community Hospital in Chicago, Illinois, April 22

They found that while both the D virus and the G virus spread widely around the world, the G strain was more dominant by mid-March. 

Next, researchers analyzed at antibody samples from six San Diego residents who had previously been infected with COVID-19.

They wanted to see if which variant would be harder to neutralize.

Results showed the new G virus was just as well neutralized – and sometimes even better – as the original D virus. 

This means the immune system doesn’t need to produce more or better-acting antibodies against the G virus, despite it being better at spreading. 

‘These findings suggest that the newer form of the virus may be even more readily transmitted than the original form,’ said senior author Dr Bette Korber, a fellow at Los Alamos National Laboratory.     

‘Whether or not that conclusion is ultimately confirmed, it highlights the value of what were already good ideas: to wear masks and to maintain social distancing.’ 

Saphire says the virus ‘wants’ to be transmissible, which is why many get a mild cases, or have no symptoms at all.

‘A virus that kills its host rapidly doesn’t go as far–think of cases of Ebola,’ she said.

‘A virus that lets its host go about their business will disseminate better – like with the common cold.’