Tom Clark, science editor at ITV News, talks about how the new strain of the virus is spreading
Scientists are now almost certain that we are now dealing with a different type of Covid-19 virus that is more contagious than any virus before.
If their assumptions are correct then this is a key moment in the pandemic. This is the first time that any of the thousands of variants of the virus around the world have acted differently this year – making it deserving of the nickname “strain” – which now may mean that we are dealing with a disease completely different from Covid-19 that we have struggled with so far.Where did it come from? In the The first analysis of the new strain, published today There is important clues.
To understand them, it is important to understand that SARS-CoV-2 ( Corona Virus That causes Covid-19) changes all the time – once or twice a month. Most of these mutants die. But some persist as new families, or strains, of the virus with their own branches of a large viral family tree. The first thing about the family this new breed belongs to is that it is unlike anything that has happened before. Those documented thus far only have one or two mutations that distinguish them from their viral ancestors. This one has a set of 14 mutations that exist together in any other family. And at least three of them could explain why the virus now has a fatal feature.
One, called N501Y, alters the spiky protein “receptor binding domain” of the virus. This is the molecular “switch” that helps the virus penetrate into our cells and cause chaos. The change caused by the mutation is thought to improve the fit of the key, helping it penetrate it more easily.
The second deletion 69-70 is thought to alter the shape of a different portion of the spike protein that might help it evade our immune system – a potential “hidden” force.
The third, the PH681H mutation, is alarmingly close to a site on the surface of the virus that might help it integrate with our cell membranes. Made her journey indoors easier.Both of these mutations have been seen in other SARS-Cove-2 families before. But not all of them together. It is a combination of their effects that may have allowed this strain to gain its evolutionary edge and become more contagious.but how? Well, it’s just a hypothesis, but it could have evolved inside one unfortunate patient.All mutations in B.1.1.5 were seen to develop separately in immunocompromised patients (such as those being treated for cancer) who had contracted the virus chronically. These patients are unable to fight off the infection, which means SARS-CoV-2 has had time to survive in their bodies and transform. Like a living laboratory for its evolution.Moreover, in places like the United Kingdom, immunocompromised patients are being treated with convalescent plasma donated by Covid-19 survivors, which is full of antibodies to the virus. If these treatments fail, not only will the patient fail – they allow the virus within them to adapt mutations to avoid those antibodies.It is only a theory, and the experimental results it can withstand will be a long time to come. But it is a plausible explanation for how the UK has found itself home to a new virulent strain of Covid-19.Today government scientists said it may be up to 70% more contagious than the current Covid variants. This means we will have to make a 70% more effort to keep it under control before the vaccine stops its spread.
