Coronavirus: How worried should we be about mutations?

It seems like every couple of days new research is released revealing the coronavirus has mutated.

Fears have been raised the ever-evolving pathogen could become more contagious or deadly.

Some have also flagged whether a virus that changes almost constantly can be controlled by a vaccine, with immunisation being hailed the way out of lockdown.

While hundreds of mutations have been identified since the virus was discovered at the end of 2019, scientists are yet to pinpoint exactly how this could impact the pandemic.

Early research suggests the infection is mild in four out of five cases, however, it can trigger a respiratory disease called COVID-19.

Coronavirus: ‘It is important people are not concerned about mutations’

The coronavirus is an RNA virus, which mutate almost constantly. In simple terms, RNA is a precursor to the more well-known DNA.

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Fears were raised when scientists from Peking University in Beijing claimed two major types of the coronavirus had evolved, with the more “aggressive” strain being the most widespread.

To learn more, a team from the University of Glasgow “examined in detail” the data presented by the Beijing scientists, concluding it “cannot be substantiated”.

“By analysing the extensive genetic sequence variation present in the genomes of the virus, the evolutionary analysis shows why these claims that multiple types of the virus are currently circulating are unfounded”, said Dr Oscar MacLean from the University of Glasgow.

“It is important people are not concerned about virus mutations; these are normal and expected as a virus passes through a population.”

Writing on Twitter, Professor Andrew Rambaut from the University of Edinburgh said genetic variations are “entirely expected”.

He added it is a “flawed inference” to suggest the mutations could make the virus behave differently.

A later study by University College London (UCL) found 198 sites in the coronavirus’ RNA “appear to have undergone recurrent, independent mutations”.

The scientists wondered whether these signify “ongoing adaptation” of the virus to humans.

It is thought to have emerged in bats and “jumped” into people, possibly via pangolins.

“Mutations in themselves are not a bad thing and there is nothing to suggest [the coronavirus] is mutating faster or slower than expected,’ Professor Francois Balloux, study author of the UCL research, told the BBC.

“So far, we cannot say whether [the virus] is becoming more or less lethal and contagious.”

Mutations that “stick” tend to offer a pathogen some kind of advantage, think “survival of the fittest”.

“At our cost the virus is doing well enough colonising the human population, I don't see the drive for it to get nastier anytime soon,” said Professor Ian Jones from the University of Reading.

He told the New Scientist around six genetic mutations arise every time the coronavirus replicates in a patient’s respiratory tract.

In response to the UCL and Los Alamos studies, Professor Lawrence Young from the University of Warwick said any talk of more virulent strains is “speculation”.

“As the virus grows to millions of copies in an infected cell, some mistakes are made in copying the genome of the virus and these result in small changes or mutations,” he said.

“These mutations often have little effect on the biology of the virus, but allow us to map the geographic spread of the virus.”

Professor Young added the coronavirus mutates at a relatively low level compared to other RNA viruses, like HIV.

Coronavirus: Mutations ‘come with the territory’

In the race to develop a vaccine, many scientists are targeting the virus’ spike protein, which allows it to enter cells.

Being exposed to the spike via a jab is thought to make the immune system recognise, and fight off, the pathogen.

If that spike is mutating, however, a vaccine that works against it may become less effective.

A team from the Los Alamos National Laboratory in New Mexico identified 14 mutations to the spike protein.

Of the “accumulating” mutations, one dubbed D614G is “of urgent concern”.

Using UK patient date, the scientists claimed people with this mutation had larger amounts of the coronavirus in their samples. It is unclear if this influenced patient outcomes.

The research has been published preliminarily online and not in a peer-reviewed journal.

Peer-reviewing involves scientists not involved in the research weighing in on its strengths and weaknesses.

When it comes to how mutations could affect a vaccine, the virus responsible for flu changes so frequently a new jab has to be developed every year.

Dr Lucy van Dorp – from the UCL study – stressed, however, studying a virus’ RNA does not tell scientists everything about it.

“I love genomes, but there is only so much they can say,” she told the BBC.

Dr William Hanage from Harvard added: “Essentially the virus has been mutating...That don't mean that much.

“Mutations are what happens when genomes replicate.

“Comes with the territory like showers with the springtime.”

While mutations may not change the trajectory of the pandemic, they are still important to study.

“Sequencing more genomes will help us to better understand the spread of the virus and whether some of the minor changes observed are important in the behaviour of the virus and how we should develop effective vaccines,” said Professor Young.

What is the coronavirus?

The coronavirus is one of seven strains of a virus class that are known to infect humans.

Others cause everything from the common cold to severe acute respiratory syndrome (Sars), which killed 774 people during its 2002/3 outbreak.

Since the coronavirus outbreak was identified, more than 4.1 million cases have been confirmed worldwide, according to Johns Hopkins University.

Of these cases, over 1.4 million are known to have “recovered”.

Globally, the death toll has exceeded 282,900.

The coronavirus mainly spreads face to face via infected droplets expelled in a cough or sneeze.

There is also evidence it is transmitted in faeces and can survive on surfaces.

Symptoms include fever, cough and slight breathlessness.

The coronavirus has no “set” treatment, with most patients naturally fighting off the infection.

Those requiring hospitalisation are given “supportive care”, like ventilation, while their immune system gets to work.

Officials urge people to ward off the coronavirus by washing their hands regularly and maintaining social distancing.