- BBC World News
New countries are added almost daily to the list of nations where the new variant of SARS-CoV-2 has begun to circulate, which first appeared in mid-September in the United Kingdom.
Known as B117 (or also VUI-202012/01), this strain has caused an unprecedented increase in the number of cases in the country (58,784 on 1/4/21), and has become the predominant variant in just three months.
At the end of December, for example, it was estimated that 60% of new cases in London and surrounding regions corresponded to the new variant.
Many remains to be discovered about this strain that has 23 mutations (17 of which appeared abruptly) regarding the virus that appeared a year ago in the Chinese city of Wuhan, but what has become evident is that it is a lot more contagious and that is crowding out older versions of the virus.
According to a study by Imperial College London, the new strain is close to 50% more transmittable than others, and this raises the R number – which represents the average number of people to whom an infected person can infect – by between 0.4 and 0.7.
Remember that this value must be below 1 to stop the pandemic (currently, in the United Kingdom it is between 1.1 and 1.3).
” There is a huge difference in how easily this variant of the virus is transmitted,” Axel Gandy, a professor at Imperial College, told the BBC. “This is the most serious change since the epidemic began,” he added.
But what is it about this strain that although it does not cause more serious cases of the disease, it makes covid-19 spread more easily among the population? As it does? And what impact does it have on the effectiveness of the different vaccines?
The exact mechanism used to achieve this is not clear. But preliminary studies suggest that one of the 17 most important mutations (in the spike-shaped protein of the virus) allows the virus to better bind to a protein on the surface of human cells, thus facilitating infection.
Any changes that facilitate entry of the virus into the cell will play in your favor.
This mutation (known as N501Y) appears to be a major adaptation, Nick Loman of the Covid-19 Genomics UK Consortium recently told the BBC.
Another mutation – called the H69 / V70 deletion – in which a small part of the spike protein of the virus is missing – has emerged several times before, for example in infected minks in Denmark.
Research carried out by Professor Ravi Gupta, from the University of Cambridge, indicates that this mutation double infectivity in laboratory experiments.
Studies carried out by the same team of researchers suggest that this suppression makes the antibodies present in the blood of survivors less effective in attacking the virus.
Another hypothesis that is being considered to explain the high number of infections caused by the new strain focuses on the viral load.
According to preliminary studies (not yet peer reviewed) conducted by the Birmingham Public Health Laboratory, 35% of samples from patients infected with the B117 strain had high virus levels, compared to only 10% of patients infected with another variant.
That is, the viral load in the nose and throat of people with the new strain was higher, a factor that facilitates contagion.
However, the researchers note that more evidence needs to be collected and analyzed to reach firm conclusions.
On the other hand, the strain has been shown to be more prevalent in children and youth.
It is not known if this is due to the fact that the variant is more efficient infecting this sector of the population, or this increase is due to the fact that in recent months in the United Kingdom schools remained open, while the activities of adults were seen reduced by different measures of confinement and social distancing.
Relationship between the new variant and the vaccine
One of the most pressing questions facing the emergence of this strain is whether the vaccines will have the same degree of effectiveness as for the original variant.
According to Lawrence Young, a professor at the University of Warwick, the information available so far seems to indicate that vaccines will be effective against the new form of the virus.
” Variants of the virus have been around since the beginning of the pandemic and are a product of the natural process by which viruses develop and adapt to their host as they replicate.”
“Most of these mutations have no effect on the behavior of the virus, but very occasionally they can enhance its ability to infect and / or become more resistant to the body’s immune response,” Young says.
More research is needed to understand why the variant is spreading so rapidly, but early indications are that vaccines will be effective against it.
Meanwhile, it is known that the transmission mechanism of the new strain is the same as for the others (by inhaling small droplets and aerosols containing the virus and floating in the air), so it is still vital to continue with the measures of isolation, hygiene and social distance.
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Eddie is an Australian news reporter with over 9 years in the industry and has published on Forbes and tech crunch.