The world has watched with concern since the UK identified a new variant of the coronavirus on December 14, which led to a surge in new infections in the south-east of the country.
Since then, two other new strains of the virus have been identified in South Africa and Nigeria, cases of all three have so far occurred in at least 13 countries.
The emergence of the new variant in the UK prompted Prime Minister Boris Johnson to change the five-day allowance for housekeeping meetings during the holiday season to a single day, and only for those in lesser areas. affected.
Other countries have canceled flights to and from the UK and have imposed strict quarantine periods on anyone who has been to the UK recently. Obviously, the world was scared off by the new strain of the virus, but was it really any surprise that the virus was able to mutate?
No surprises here
The short answer is no. “The more a virus is allowed to run unchecked in a population, the greater the risk of mutation – by undergoing changes in its genetic makeup.
It’s no secret that the UK has one of the highest coronavirus infection rates in the world. Different viruses will mutate at different rates. The SARS-CoV-2 virus that causes the COVID pandemic in the first place is accumulating genetic changes at a rate of one to two mutations per month, around the world.
The vast majority of mutations are small and have no apparent effect on the virus itself or on the host it infects.
Over time, however, more and more mutations will occur, which means that thousands of people have now done so since the onset of the coronavirus.
Viral mutations can occur in several ways. In the case of the new strain identified in the UK, it is believed to have occurred when a person with a particularly weak immune system was infected with the virus. Instead of their bodies fighting it, they have become a breeding ground for the virus, allowing it to multiply inside them multiple times.
Mutations also occur naturally in viruses as they replicate and spread in a population. The speed at which viruses replicate inside cells means that mistakes are made when duplicating their genetic code – these are mutations.
Many mutations are, in fact, harmful to a virus, and these versions of the virus simply die. However, every now and then a random mutation can occur that is beneficial for a virus.
When a beneficial mutation occurs – a mutation that makes it superior to the original form of the virus, the new variant becomes the dominant strain within a population. This is what appears to be happening in large parts of the UK, where the new variant is expected to have become the dominant virus in large parts of the UK by mid-January as more and more people are infected.
A “superior” strain of virus is one that is more infectious (more likely to establish infection) because it has new or better methods of spreading, is more efficient at infecting hosts, replicates faster, or even resists. to treatments.
How the new variety works
The reason is that the specific mutations that have appeared in this new variant seem to make it between 50% and 70% more infectious than the original strain from which it comes.
An initial analysis of the new British variant has been published and shows that the new British strain is the result of 17 different mutations working together, not just one. It often takes more than a single mutation to alter the structure of a virus significantly enough to produce a new strain.
One of the most important of these 17 new mutations is known as the N501Y alteration. This mutation affects one of the most important parts of the virus – its “spike” protein.
The spike protein is the key with which the virus opens the doors to and enters our human cells, which infects them. Before it can enter and infect a cell, the coronavirus must bind to a receptor outside the cell – the ACE2 receptor, which, when bound, allows the virus to enter inside. The new N501Y mutation makes it easier for the virus to bind to ACE2 receptors and to enter cells more easily. This may explain its increased infectivity – the ability of a pathogen to establish infection.
Another important change in the new UK variant is called the H69 / V70 deletion. Here, a small part of the very important spike protein is removed from the virus itself.
A study (PDF) conducted in Cambridge in mid-December found that this particular mutation could make our antibodies to the virus less effective at destroying it.
Scientists are urgently working on the new variant to see if any of the other mutations may be significant.
So far, we know the virus is more transmissible in its new form, but, so far, there is no evidence to suggest that the new variant is causing more severe symptoms.
Scientists also believe that the vaccines that are made to inoculate people with the coronavirus will continue to provide us with protection against this new variant.
Vaccines stimulate the immune system in humans to attack different parts of the virus, so even though the spike protein may have mutated, for example, vaccines are still likely to work.
Dr Anthony Fauci, America’s top infectious disease expert, said data from Britain indicates vaccines will still block the virus. But the United States will also be testing to be sure.
The key is to vaccinate as many people as possible as quickly as possible before the virus mutates beyond the scope of current vaccines. If the virus finds a vaccine “loophole” by discovering other mutations, it is likely that the vaccines will need to be modified to accommodate any new strain. Experts said it was “relatively easy” to do and we already do it for other vaccines like the flu shot every year.
Vaccines therefore offer hope, but it will still be some time before at least 60 to 80 percent of the world’s population are vaccinated, giving us “herd immunity”.
In the meantime, the now standard methods of social distancing, hand washing, wearing a mask and ventilating indoor spaces remain important. We all need to rethink our behavior and minimize contact with those who are not in our homes or support bubbles, only leave our homes for essential purposes, and bunker down a little longer.
This new variant may be more infectious, but it still relies on close human contact to spread. We all have the power to help reduce the spread of this virus simply by adhering to these rules of social distancing. We must step up our efforts. Now is not the time to get complacent.