The word ‘mutation’ may instil fear in many, as the term is often associated with science fiction and disaster movies, but in the life cycle of a virus, mutation is a natural occurrence.
On 22 November, UK scientists revealed that they were monitoring 4,000 mutations of Covid-19, with some concern that the new strains may resist vaccines.
Earlier in November, a mutated strain of coronavirus made headlines, after study findings revealed the version was potentially more infectious than the original, and had been detected in several areas worldwide.
But is a mutated virus strain really more dangerous, and should you be concerned?
What is a virus mutation?
A mutation is a change in a virus’s genome. Genomes are the set of genetic instructions that house all the information the virus needs to function.
Mutations happen when the virus makes contact with a host and starts to replicate. The set of instructions is then copied, but mistakes can often happen in the process. Where the errors occur within the genome will determine whether they have a positive or negative impact on the virus’s ability to survive or replicate.
SARS-CoV-2 is an RNA virus, which is more prone to mutations, unlike DNA viruses, like smallpox. As it has passed from person to person over the past eight months or more, Covid-19 has been, and continues to be, mutating.
Virologist Dr Sarah Pratt (who is principal lecturer at the University of Brighton and a fellow of the Institute of Biomedical Science) explains, “RNA viruses, like Covid-19 or HIV, are very prone to mutations because they don’t get corrected by us. Whereas in DNA viruses there is a very limited amount of mutations.”
Because mutations are part of the natural process of an RNA virus, Dr Pitt says there’s no cause for alarm.
“This is perfectly natural what we are seeing in regards to mutation of this coronavirus. It shouldn't be a point of concern, it happens a lot,” she adds.
Are mutated viruses more dangerous?
Mutations don’t tend to add any changes that will lead to a virus being more harmful. However, the changes within the virus may affect how easily it is transmitted from person to person, which is why new strains of Covid-19 are often dubbed ‘more infectious.’
Dr Pitt explains, “When the virus is inside you, the factors of what lead you to become seriously ill are the same, regardless if it's a mutant form or not.
“This isn’t to say that there isn’t the capability of a new dangerous mutation appearing, but there is no evidence so far that any of the mutations are more harmful in creating a worse illness.”
Why are there so many mutations of Covid-19?
There are currently over 20,000 mutations of SARS-CoV-2. You can see a breakdown of the mutations around the world via the international database.
The database records mutations with tiny changes. Dr Pitt says that most of these “don’t make a blind bit of difference to the actual virus itself.”
The mass collection of data through the international database should not be a cause for concern. People are collecting the data simply because it's interesting, the database is available, and sequencing viruses is much easier than it was five or 10 years ago, Dr Pitt explains.
What about strand D146G?
Earlier in the year a study published in Cell journal suggested that Covid mutation strand D641G was increasing in frequency at “an alarming rate” around Europe. Many news outlets were quick to release worry-filled articles, prompting fear in many readers.
The mutation was reported as becoming the dominant SARS-CoV-2 strain in Europe. It was also said that it had taken a hold in the United States, Canada and Australia.
D614G appeared in the news again earlier this month, after another study revealed the new strain was believed to account for 85 per cent of coronavirus cases globally, and seems to be more infectious than the original.
Dr Pitt explains that the D614G strand emerged in the first wave of transmissions, after many people had holidayed in Europe. The particular mutation shares similarities with another strand, called 20A.EU1, which also made headlines.
Plainly put, both mutations are more likely to stick to the outside of the cells inside you, with D614G seemingly binding more easily than other strands.
“It is more likely to get in the cell, and then it seems to produce more new viruses, so it’s more infectious,” Dr Pitt agrees.
“However, there is no evidence that this mutant is more dangerous.”
Virologist David Montefiori, who worked on the Cell article for D641G, and his team of researchers eventually said they regretted describing the mutation's rise as “alarming,” after the panic it caused.
Be careful what you read
Dr Pitt believes “scaremongering headlines” can be misleading to readers, and that reporting on Covid mutations can be “overdramatised sometimes.”
“People should be wary of what they read when it comes to mutations,” she adds.
“In the D614G case, the user of the word ‘alarming’ can be misleading. I spend a lot of time telling my students when they are writing not to use judgemental language and focus on the objective facts - ie, ‘It is more infectious.’”
Will mutations make a Covid-19 vaccine useless?
The current search for a vaccine for Covid-19 should not be affected by mutations of the virus appearing, experts say. Vaccines should not have to be created for different mutations, but instead focus on where in the spike protein the change actually occurs.
There is also no reason to think that the virus won’t be fully eradicated because of mutations. Dr Pitt says there is still good reason to believe that we can fully eradicate Covid-19.
“At the moment it looks like if we find a way of controlling the spread of the virus from person to person through control measures or through quarantining people who are positive, and perhaps the help of the vaccine, we can get rid of it just as easily. I don’t know whether we will, but I like to think we should be able to,” she explains.
Ultimately, it’s down to us to get a handle on coronavirus. If we don’t, Dr Pitt says, it will be “human behaviour related and not virus related.”