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The new strain of nCoV in the UK could become popular, scientists say, but it will take years to become resistant to existing vaccines.
As soon as the vaccine was approved, opening the door to hope of escaping the pandemic, British officials urgently warned of the new nCoV strain, more contagious than before.
As the virus quickly spread through London and surrounding areas, Prime Minister Boris Johnson was forced to impose the country’s strictest restraining order since March.
“When the virus changes the way we attack, we also have to adjust our defense,” he said.
London train stations were packed with people trying to leave the city before the ban went into effect. On December 20, many European countries began closing borders to people from the UK to prevent the new virus from entering.
In South Africa, a similar mutation has occurred. Viruses have been found in 90% of samples on the continent since mid-November.
Variants are used to refer to strains of the virus that have some variation in their “genetic sequence” from the original discovered in Wuhan, China, in December 2019. Variation in the “genetic sequence” of the virus is a natural phenomenon because during the infection and reproduction, they copy their own genome and make mistakes. So far, the number of nCoV variants detected by genetic sequencing of randomized patients is several thousand, however the actual number may be higher.
Just because some strains have become popular simply by accident does not mean that the changes made the virus more prominent. But when the vaccine is available and many human populations appear immune, the pathogen is more difficult to survive. Scientists believe that the virus will have mutations that will easily or favorably evade the immune system.
“This is the risk we need to be aware of,” said Jesse Bloom, an evolutionary biologist at the Fred Hutchinson Cancer Research Center in Seattle. Scientifically, we need to track down and determine which trait is influential.
The nCoV strain in England has around 20 mutations. Among them, some mutations changed the way of exposure and infection of human cells. Muge Cevik, an infectious disease specialist at the University of Saint Petersburg. Andrews in Scotland, a scientific adviser to the UK government, says mutants can be replicated and transmitted more efficiently. Authorities say its infection rate could reach 70%. But this analysis is only based on an epidemiological model that has not been validated in laboratories, added Dr. Cevik.
Londoners wear masks and walk the empty streets on the first day the city imposes a third-degree restriction. The Times of New York City
“In addition to that, I think we need more test data. We cannot rule out the possibility that high levels of infection are dependent on human behavior,” he said.
Scientists in South Africa believe that the activity of the new people is the cause of the pandemic, not the new strain.
The new UK report also raises concerns that nCoV could evolve to levels of resistance to recently launched vaccines. They speculate on some changes in the genetic code of the virus that protects it against certain antibodies.
But experts say it takes years, rather than months, for the virus to become resistant to the vaccine.
“Don’t worry about some supernatural mutation crippling all of your antibodies and immune systems,” says Dr. Bloom.
“It’s going to be a long process, lasting over the years, and it will require a lot of mutations. It’s not like an on-off switch,” he added.
A new strain of the virus is only cause for concern when people who have already been infected or who have been vaccinated are re-infected even though there are still antibodies in the body.
But scientific analysis is of little importance to Britain’s neighbors. Concerned about travelers carrying a new entry variant, the Netherlands said it would suspend flights departing the UK from December 20 to January 1.
Italy also closed routes and Belgium issued a 24-hour ban on people arriving from the UK by air and train. Germany is making a similar move.
In the UK, officials have announced that they will increase the number of police officers in centers such as train stations to ensure that residents only take essential trips. Health Minister Matt Hancock, on December 20, said those who fled London were “very irresponsible.” He also believes that the new restrictions could last for months.
Similar to other types of pathogens, nCoV can change shape. Genetic mutations are hardly important, but some can benefit the virus.
Scientists are concerned about the latter possibility. Especially when massive inoculation can make the nCoV adapt. Mutations can help the virus evade or counteract an immune response.
nCoV is infecting a cell in the human body. Image: The Times of New York City
Mutations also have the ability to affect the susceptibility of the virus to antibodies. In some cases, the virus self-removes parts of the genetic code to adapt. This phenomenon has appeared at least three times: in Danish weasels, the British people and a patient with immunosuppression, they become less sensitive to plasma therapy.
“The pathogen is continually transmitting, developing and adapting to the environment,” said Ravindra Gupta, a virus specialist at the University of Cambridge.
Scientists initially thought that nCoV was fairly stable and could not escape the immune response produced by the vaccine, said Dr Deepti Gurdasani, a clinical epidemiologist at Queen Mary University of London.
“But in recent months, it is clear that the mutation is still occurring. As natural selection increases with mass vaccination, I think this mutation could become more common,” he said.
The good news is that the technology used in the Pfizer-BioNTech and Moderna vaccines is much easier to adjust and upgrade than the conventional injection. New vaccines also induce a large immune response, so nCoV may need mutations for years before a vaccine modification is needed, says Dr. Trevor Bedford, an evolutionary biologist at the Fred Center for Cancer Research. Hutchinson says.
Thuc Linh (According to the NY Times, BMJ)
