Since January, when the genome of SARS-CoV-2 was sequenced and published online, scientists have been able to closely track changes to the biological makeup of the virus.
On the website NextStrain, many of those mutated strains of the virus are listed and linked geographically to where they were identified after nasal swabs from people tested for the virus were analysed.
When you zoom in on New Zealand, you can see all the nucleotide mutations noted from local testing. Lines curve in from around the world, like routes on an air travel planning map, tracing where the mutations likely came from.
The big worry around Covid-19 is that we get “escape mutants” with the virus. These could thwart efforts to fight it using a vaccine because the antibodies created in the body wouldn’t recognise them.
So far we seem to have dodged a bullet, but one mutation is getting a lot of attention from scientists. They call it G614 or the European variant, because that’s where it was first detected.
The mutation affects the tiny spike proteins on the outside of the virus that it uses to latch on to cells so it can infect them and then replicate itself. This one has stronger spikes.
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| Andy Hollings, a science technician at Waimea College, has a new job working for the Covid-19 Vaccine Corporation |
Genetic analysis shows that this mutation has rapidly replaced the original version of the virus, which was called D614 and was first detected in Wuhan in January. Crucially, the G variant doesn’t appear to be any worse for you than the original variant, patient survival appears to be the same as with the D variant. But based on lab experiments, some scientists estimate it to be three to nine times more effective at infecting people.
That’s natural selection for you, only the mutations that make life easier for the virus to thrive and spread tend to survive.
The G-variant’s advantage is that it multiplies faster in the nose, sinus and throat of those it injects, making it easier to spread to others through sneezing and coughing.
That same Darwinian trait may also see the virus become less “pathogenic” or likely to cause disease the further it spreads, as it is less likely to need to embed itself in the lungs which causes the serious respiratory illnesses associated with Covid-19.
G614 appears to have made its big debut in March.
“Through March 1, 2020, the G614 variant was rare outside of Europe, but by the end of March it had increased in frequency worldwide,” researchers writing in the journal Cell noted earlier this month.
Bottom line, the virus is now more contagious but not more deadly.
In our bubble at the bottom of the world that may not mean much to us. But as we open up, scientists will need to be vigilant in detecting further mutations and factor them into public health measures and the effort to develop an effective vaccine.
