In recent days, the world has been watching with increasing curiosity and alarm as scientists in the UK describe a newly identified variant of coronavirus that appears to be more contagious than the most well-known, as well as genetically distinct. Initial studies of the new variant led Prime Minister Boris Johnson to tighten restrictions on Christmas and call on authorities in the Netherlands, Germany and other European nations to ban travel in the UK.
At the moment, the new option is the focus of intense debate and analysis. This is part of what scientists have discovered so far.
Is the UK version a new kind of supervirus?
Not. This is just one of many that have emerged as the SARS-CoV-2 coronavirus has spread around the world. Mutations occur when the virus reproduces and this variant – known as B.1.1.7 – already has its own distinctive set.
What is unusual about this?
The variant came to the attention of researchers in December, when it began to appear more frequently in samples taken from regions in the south of England. It turned out that they were taken from patients in September.
When the researchers carefully analyzed its genome, they were shocked by the relatively large number of mutations it developed – 23 in total. Most coronavirus mutations are harmful to the virus or have no effect. However, it appeared that several mutations in B.1.1.7 could affect how the virus spread.
Is it more contagious than other viruses?
It looks like. In preliminary studies, researchers in the UK found that the virus is spreading rapidly in parts of southern England and that it crowds a large number of other variants that have been circulating for months.
However, the fact that one strain of the virus is becoming more common is not evidence that it is spreading faster than others. It could only spread by chance. For example, a variant could appear in a very populated city, where it can be easily transmitted and thus create more copies of it.
However, the epidemiological evidence collected so far in England seems to suggest that this variant is very good at spreading. In places where it has become more common, the total number of coronavirus cases increases. Neil Ferguson, a public health researcher at Imperial College London, estimates that the high transmission rate of this variant is between 50 and 70% compared to other variants in the UK.
Some scientists have considered the possibility that the increase in transmission is the result, at least in part, of the way it infects children. Usually, children are less likely to contract or transmit the virus than teenagers or adults. However, the new strain could make children “as sensitive as adults,” said Wendy Barclay, a government adviser and virologist at Imperial College London.
Does it cause a more serious illness?
There is no clear evidence to confirm this, at least so far. However, there are reasons to take the possibility seriously. In South Africa, another strain of coronavirus has developed a special mutation that is also found in B.1.1.7. This variant is spreading at maximum speed through the coastal areas of South Africa. Moreover, in preliminary studies, doctors found that people infected with this variant carry an increased viral load – a higher concentration of virus in the upper respiratory tract. In many viral diseases, this is associated with more severe symptoms.
Where does this unusual variant come from?
There is an intense debate around this question. One possibility is that the variant has developed its series of new mutations in a special set of hosts.
In a typical infection, people get the coronavirus and become contagious a few days before they show symptoms. Later, the virus becomes less abundant in the body because the immune system commands a defense. Unless patients have a severe case of COVID-19, they will be completely free of the virus within a few weeks.
However, sometimes the virus infects people with weak immune systems. In their body, the virus can develop for months. Case studies of these immunocompromised people have shown that the virus can accumulate a large number of mutations when it reproduces in their body over a long period of time.
Some researchers have found that natural selection can promote mutant viruses that manage to evade the immune system over time. They also suggested that the evolution of the variant could have received an additional boost from the drug given to those patients. Some mutants may be tolerant to drugs such as monoclonal antibodies.
Other scientists have pointed out that the virus could have developed new mutations by spreading through a certain population of animals, such as mink, before re-entering the human population. These “animal reservoirs” have become a hotbed of interest as more animal infections have been detected.
Is the variant already circulating in the United States?
Not yet, as far as is known. However, this does not mean that he did not arrive in the United States. British scientists have established a much better system to monitor coronaviruses for new mutations. Maybe someone who traveled from the UK brought it. Now that the world knows how to look for the option, it could appear in several countries.
Will the variant make the new vaccines ineffective?
Not. Most experts doubt that it has a significant effect on vaccines, although it cannot yet be ruled out that there may be an effect.
The Food and Drug Administration has authorized two vaccines, one from Moderna and the other from Pfizer and BioNTech. Both vaccines create immunity against the coronavirus, teaching our immune system to create antibodies against a protein called the tip, which is found on the surface of the virus. The spike protein attaches to the cells and opens a passage in them. Antibodies produced in response to vaccines stick to the tip of the tip. The result: viruses cannot enter.
A mutation in a coronavirus may change the shape of its peak proteins, making it difficult for antibodies to attach to them. In addition, eight of the B.1.1.7 mutations are found in the spike gene. However, our immune system can produce a whole range of antibodies against a single viral protein, making it less likely that viruses will easily escape their attack. At this time, experts do not believe that the variant can steal vaccines. To confirm this, researchers at the Walter Reed Army Research Institute are analyzing changes in the structure of its spike protein.