What kind of virus was discovered in Vietnam is not completely clear. The government news site VGP News, citing Acting Minister of Health of Vietnam Nguyen Thanh Long, reported next: “Genomic analysis showed that this is a new type of COVID-19, more infectious.” From this we can conclude that we are talking about a variety of SARS-CoV-2, and not a completely new coronavirus. But whether it is really easier to pass from person to person is more difficult to judge.
Back in March, scientists from China announcedthat SARS-CoV-2 split into two genetically distinct branches, L and S, with the former more common. Then it was suggested that the L-variant was more contagious. But this guess was soon abandoned: the coronavirus has recently spread to humans – it is probably just an accident that the S-variant came across less often.
Those variants of the coronavirus differed in only two “letters” in the genome, where these letters are 30 thousand. The reason is in mutations, and SARS-CoV-2 mutates constantly. Most of these changes do not affect the properties of the virus, but it is not easy to check this.
Recently, the D614G mutation is often discussed. It changes one amino acid “building block” in the thorn of the coronavirus, which it clings to human cells. Scientists have shown that variant G614 is more infectious in vitro than D614. Also, the G614 variant began to prevail in many countries of the world. Finally, people infected with this virus find more viral RNA in swabs from the throat and nose. Because of this, it can be assumed that the G614 is more infectious than the D614 under normal conditions.
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But epidemiologists at Yale, Harvard, and Columbia thinkthat this is a hasty conclusion. Test-tube experiments are one thing, but under normal conditions, things can be different. The G614 variant could have spread simply because the epidemic was contained in Europe worse than in China, and from Europe the virus reached the United States, where it also became predominant. As for smears, a high concentration of viral RNA in mucus does not necessarily indicate an increased infectivity. In addition, people often transmit the virus before symptoms appear, and it is not known whether there is a lot of the virus in the nasopharynx at this stage of the disease.
If the mutation does make the coronavirus more infectious, then it will be harder to contain, but it’s too early to judge. But it is already clear that those infected with this variant of SARS-CoV-2 are sick in the same way, and not more severely. Other mutations in SARS-CoV-2 have not been tested as closely, so it is unlikely that yesterday’s news is related to them.
Perhaps it was a variant of the G614 virus that was found in patients in Vietnam. “I asked my colleague Marc Choisy, an epidemiologist who works in Vietnam. They analyzed the genomes. It turned out that the virus in the tested samples belongs to the wrong puts (branches on the family tree – approx. TASS), which is usually found in Vietnam. This one is closer to Bangladeshi, “- said in a letter to TASS, evolutionary ecologist, head of a research group at the University of Montpellier, Samuel Alison.
The French scientist did not see the data of his colleague, but believes that we are really talking about the D614G mutation. In his opinion, the main thing in the news from Vietnam is different. In this country, just over 300 cases of COVID-19 were registered in four months. This is an outstanding achievement, which is why the 15 new patients reported the previous day look alarming.
TASS turned to Marc Choisy for details, but he has not yet answered.
Marat Kuzaev
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