A novel coronavirus taken with an electron microscope. National Institute of Allergy and Infectious Diseases, [연합뉴스]
– The novel coronavirus (Corona 19) strain, which was discovered in the UK and straining the world, was confirmed that the two first appeared together at the same time, but only the one with stronger transmission power survived.
Simultaneous outbreak of virus strains in September
Variant 2 dominates the country from November
Similar variants appear in South Africa
The 2nd and 3rd waves start due to the variant
May cause a new trend across borders
– Another strain prevalent in South Africa also contains mutations that overlap with the British variant, but is evaluated as being more infectious.
Experts argue, “As there are many cases in which new strains appear in each country and lead to the massive spread of Corona 19, monitoring should be strengthened, such as expanding virus gene analysis in preparation for the emergence of strains.”
Two variants appeared in September
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On the 23rd, at the entrance to the Port of Dover in the UK, vehicles are waiting to be tested for new coronavirus infection. The spread of the new coronavirus strain in the UK has prevented the movement of vehicles from the UK by European Union (EU) countries. Reuters = Yonhap News
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Schematic diagram of novel coronavirus strains. The purple color represents the British variant 1, and the red color represents the variant 2. The orange color is a similar variant from South Africa, and the lower ocher color is from Australia. All four strains have a mutation in the viral spike protein in which amino acid 501, the receptor binding site, is changed from asparagine to tyrosine. Source: University of Hong Kong Paper
– On the 22nd (local time), a research team from Hong Kong and China such as the University of Hong Kong announced that in the UK, two corona 19 virus variants (variant) were simultaneously prevalent in the UK through a paper posted on the preliminary publication site (medRxiv).
Analysis of viral genome (genome) data published by British researchers revealed that both strains had the N501Y mutation in the receptor binding domain (RBD) among the virus’s spike proteins.
RBD refers to a site that directly binds to angiotensin converting enzyme 2 (ACE2), a receptor for human cells, among spike proteins.
The N501Y mutation means that the 501st amino acid of the protein has been changed from asparagine (N) to tyrosine (Y).
According to a Hong Kong research team, variant 1 had the N501Y mutation, but amino acids at positions 69 and 70 were retained.
Variant 2 also had a deletion mutation in which amino acids 69 and 70 were removed along with the N501Y mutation.
Variant with 75% higher propagation power takes control
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![Novel coronavirus particles. National Institute for Allergic Infectious Diseases [AP=연합뉴스]](https://i0.wp.com/pds.joins.com/news/component/htmlphoto_mmdata/202012/25/85c85d5e-d043-4421-a270-129d6ffac72f.jpg?w=900&ssl=1)
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Novel coronavirus particles. National Institute for Allergic Infectious Diseases [AP=연합뉴스]
– The research team calculated the reproductive indices of 501N without mutations and the two strains, and compared the infectivity with each other.
The reproductive index is a measure of how many people infected with the virus pass on to others.
As a result of comparison, Variant 1, which spread mainly in Wales between early September and mid-November, was analyzed to be 10% more contagious than 501N.
The proportion of strain 1 among the corona 19 virus samples also did not exceed 2% of the total.
In contrast, Variant 2, which was first discovered and started spreading in the southeastern part of England on September 20, was found to be 75% more contagious than 501N.
Variant 2 accounted for only 0.1% of all viruses in early October, but increased to 49.7% at the end of November and 62% at the beginning of December.
Variant 2, named B.1.1.7 (VUI-202012/01), has now become the dominant variant in the UK, beating 501N as well as variant 1.
The research team believes that N501Y is better able to bind to receptors, making the virus more likely to invade and infect human cells.
South African variant spreads from November
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In March, the South African National Defense Forces patrolled men’s hostels in Alexandra Town, a populated area in eastern Johannesburg to control the spread of the novel coronavirus, and enforced strict containment. AP=Yonhap News
– A new variety has appeared in South Africa and has spread rapidly since November.
South Africa is also the most affected area in Africa.
As of the 24th, 954,258 people were infected, and 25,656 people died.
According to a paper posted on medRxiv by a South African research team, including KwaZulu-Natal University, on the 22nd, the South African variant also showed an N501Y mutation in its receptor-binding domain.
However, unlike British Variant 2, amino acids at positions 69 and 70 were maintained, and in RBD, 8 amino acids of the spike protein were changed in addition to N501Y.
This variant, named ‘501.V2’, first appeared in Nelson Mandela Bay, Eastern Cape, South Africa, which was severely hit by Corona 19 after the first pandemic (wave) in June-July. Has a dominant position in Western Cape as well as Eastern Cape.
“The South African variant is more contagious than the British”
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On the 13th of last month, citizens are waiting to be tested for the novel coronavirus at Livingston Hospital in Port Elizabeth, South Africa. At the time, in Eastern Cape Province, cases of Corona 19 soared and deaths soared. AP=Yonhap News
– “The function of the mutations in the variant has not yet been clearly evaluated, but it suggests an increased infectivity,” the South African team explained.
In particular, the E 484K mutation, in which amino acid 484 was changed from glutamic acid (E) to lysine (K) along with the N501Y mutation occurred at the site that binds to the human receptor (RBD), and thus evidences have been suggested that it is highly contagious.
The research team also said, “There is a possibility that multiple viral mutations occur within the same host, and as this phenomenon repeats, a variant with multiple mutations may have appeared.” “There is no evidence that it is related to chronic infections.”
Meanwhile, some experts point out that “compared to the British variant, the South African variant binds to human cells better and has a stronger transmission power.”
In this regard, the British government temporarily suspended entry from South Africa from 9 am local time on the 24th when a variant virus entered the country from South Africa.
The move appears to be due to the discovery of a new strain of two people who recently visited South Africa.
Second and third waves are due to the emergence of new variants
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New confirmed cases of Corona 19 after August. Graphic = Reporter [email protected]
– On the 21st, Professor Konishi Tomokazu of the Department of Biological Resources Science at Akita Prefectural University in Japan said in a paper that was previously published on the bioRxiv site, “A new variant emerged around the world, surpassing the line of defense that had previously been effective. There is a tendency for the second and third waves to reoccur.”
Professor Cornish said, “Corona 19 virus spread evenly all over the world until last April, and after the border was closed, each country independently mutated,” he said. “The mutation seems to have given the virus a higher infectivity.”
“Mutations may be the result or cause of the second wave,” he said. “In the UK, the United States, France, and Australia, strains appeared several weeks before the peak of the sudden increase in confirmed cases, and the virus was replaced by the strain. “It suggests that the mutation is the cause of the peak.”
In contrast, in the case of South Africa, a mutation appeared suddenly and reached a peak immediately, according to Professor Cornish’s analysis that the mutation may be the result of the peak.
The greater the number of confirmed cases, the greater the likelihood of mutations will occur, and thus variants may appear.
Professor Cornish said, “In the case of South Africa, there is a possibility that the national surveillance system could not detect it even though the variant appeared,” he warned. “The variant of one country may pass over to another country and cause another pandemic.”
The South African research team also emphasized in the paper that “it is important to have a global surveillance system in place to detect new strains early and prepare for a global pandemic.”
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Corona 19 cumulative confirmed patients since August. Graphic = Younghee Kim [email protected]
– Reporter Kang Chansu [email protected]
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