The new coronavirus variant announced by British scientists is more infectious than other known variants, so the world is full of curiosity and alertness. Countries all over the world are stepping up testing to see if it has been circulating in their own countries.
At present, all work is still in the early stages, which contains huge uncertainties and a long list of unresolved issues. Viruses will always mutate, so paying attention to whether the behavior of the virus is changing is the top priority of research work.
23 mutations in the British crown variant
Regarding this new coronavirus variant, three things merged together and caught the attention of researchers: it is rapidly replacing other versions of the virus; a very important part of the virus is likely to be mutated; some of the mutations are already in the experiment Show that the ability of the virus to infect cells can be enhanced.
In summary, these factors together constitute a new coronavirus that is easier to spread. It is called B.1.1.7. However, we are not absolutely sure about this. In order to confirm that the variant is indeed more infectious, the researchers conducted laboratory experiments on it to closely observe how it infects cells. Researchers have used this kind of experiment to study the mutant 614G that appeared earlier in the epidemic.
Usually, new virus variants only need to appear in the right place at the right time to become more popular, such as London, which was only “level 2” blocked until recently.
The reason for London’s current “Level 4” blockade is precisely to reduce the spread of new variants. This virus variant caught the attention of researchers in December 2020. At that time, the frequency of this variant became higher in the samples tested in parts of southern England. In the end, the researchers discovered that this variant had been collected from patients as early as September of that year.
When the researchers looked closely at its genome, they were shocked by the 23 mutations that had occurred. Most of the mutations produced in the new coronavirus are either harmful to the virus or have no effect at all, but many mutations in the B.1.1.7 variants seem to affect the way the virus spreads.
But is this variant a new super virus? No, this is just one of the many variants of the new crown virus that has spread around the world. Mutations occur when viruses replicate. This variant called B.1.1.7 has acquired its own unique set of mutation patterns.
British variant virus increases infectivity
A virus lineage is becoming more and more common, and it does not prove that it spreads faster than other viruses. Only by luck, it can spread more widely. For example, the spread of a variant may start in the middle of a crowded city, where it is easy to spread, and more copies can be copied.
Nevertheless, the epidemiological evidence collected from England so far seems to indicate that this variant is very good at spreading. Neil Ferguson, an epidemiologist at Imperial College London, estimates that compared with other variants of the virus in the UK, the spread of this variant has increased by 50% to 70%.
In the B.1.1.7 variant, the spike protein has changed-this is the key used by the virus to enter human cells. A mutation called “N501Y” changes the most important part of the “receptor binding domain” in the spike protein, which is where the spike protein first contacts the surface of human cells.
Any change that makes it easier for the virus to enter the body’s cells may make it more contagious. Professor Lohman said: “No matter from which point of view, this is an important mutation.”
The new variants may make children “as susceptible to infection as adults.”
Another mutation is that a small part of the spike protein is removed. This mutation has appeared several times before, including the new coronavirus that was previously infected by mink. The work of Professor Ravi Gupta of the University of Cambridge showed that this mutation doubled the infectivity in laboratory experiments.
The research of the same group shows that this deletion mutation can make survivors blood? ? The effectiveness of the antibodies in attacking the virus is reduced. Professor Gupta told us: “The number of mutations is increasing rapidly. This worries the government, we are worried, and most scientists are also worried.”
Some scientists have suggested that part of the possibility of the increased infection rate is due to the result of it infecting children. Generally, children are less likely to be infected or carry the virus than teenagers or adults. Wendy Barclay, a government consultant and virologist at Imperial College London, said the new variant may make children “as vulnerable to infection as adults.”
South Africa variant virus will make the vaccine ineffective?
In South Africa, another lineage of the new coronavirus has acquired a special mutation, which also appeared in B.1.1.7. This variant virus is spreading rapidly in the coastal areas of South Africa. In preliminary studies, doctors there found that people infected with the virus carry a higher amount of the virus—the virus has a higher concentration in their upper respiratory tract. In many viral diseases, this is positively correlated with more severe symptoms.
Will this variant invalidate the new vaccine? Most experts agree that the variant will not have a major impact on the vaccine, although any possibility cannot be ruled out.
Both Pfizer and BioNTech vaccines can teach our immune system to produce antibodies against the spike protein located on the surface of the virus to generate immunity to the new coronavirus.
Antibodies produced against the vaccine will stick to the tip of the spike protein. As a result, the virus cannot enter human cells. The mutation of the new coronavirus variant may change the shape of its spike protein, making it difficult for antibodies to grasp them tightly. And B.1.1.7 has 8 mutations in the spike protein.
However, our immune system can produce multiple antibodies against a single viral protein, thereby reducing the possibility of the virus escaping the attack. At present, most experts believe that the British variant virus will not avoid the antibodies produced by the vaccine. In order to confirm this, some researchers are analyzing the changes in the structure of its spike protein.
Some researchers say it is too early to ignore the risks of vaccines. If the British variant virus evolves to avoid the immune system of patients with weakened immunity, these mutations may help it escape the vaccination.
The vaccine will not become useless, but the effect may be reduced.