How is WHO’s new system for classifying coronavirus variants with Greek letters

The World Health Organization announced today that it has created a new naming system for variants of interest and variants of concern of the coronavirus. Each variant will be given a name from the Greek alphabet. He did this to remove some of the stigma of emerging new variants associated with cities and countries that has been carried so far.

Maria Van Kerkhove, head of the coronavirus at the WHO, said that “No country should be stigmatized for detecting and reporting variants.” He said the new variant labels are “straightforward, easy to say and easy to remember. and they are based on the Greek alphabet, a system that was chosen after careful consultation and consideration of several possible systems ”.

As part of the new system, the variant that was first reported in Kent, England was renamed Alpha. Meanwhile, the variant that originated in South Africa is now called Beta. The Brazilian variant – known as the Manaus variant – is Gamma and the variant first reported in India is Delta.

The new virus has infected more than 170 million people and killed nearly 3.7 million since its emergence in China in late 2019. Since the start of the pandemic, there are fears that mutations and variants that occur naturally will cause changes to fail. appear in viruses as they are. reproduce as they spread.

All viruses – including SARS-CoV-2, which causes COVID-19 – change over time. Viruses make copies of themselves in a process called “replication” in which copies can be made with small changes, which is common in viruses. These changes are called “mutations”. A virus that has undergone one or more mutations is considered a “variant” of the parent virus, as defined by the WHO.

In the coronavirus that causes COVID-19, there is a 30,000 letter string that represents the chemical properties that make up its genome. To reproduce, the coronavirus attaches itself to the outside of a human cell and then enters it: it hijacks the cellular machinery and directs it to make copies of the virus.

When a virus circulates widely in a population, infecting many individuals, the likelihood of mutations occurring increases. The more opportunities the virus has to spread, the more it replicates and, therefore, the more likely it is to undergo variations. For the most part, viral mutations affect little or nothing to a virus’s ability to infect and cause symptoms.

However, depending on where they occur in the genetic material of the virus, these changes can affect the properties of the virus, such as its ability to transmit (for example, it can spread more easily) and the severity of the symptoms of the virus. . infection (that is, the disease is more or less severe).

The detection of variants is done through a global network of laboratories for SARS-CoV-2 which is in contact with the WHO. Several groups of researchers have sequenced SARS-CoV-2 and submitted the sequences to public databases, including GISAID. Thanks to this global collaboration, scientists can better monitor the virus and the changes it is undergoing.

Today is called “Variant of concern” if a variant has the capacity for greater transmissibility, increases its virulence or produces changes in the clinical presentation of the disease, or reduces the effectiveness of social and health measures, such as vaccines, diagnostic tests or therapeutic products, as the WHO clarified today. To date, the health agency recognizes 4 worrying variants.

There are also 6 other variants which have been classified as “of interest” and which were detected in March and April last. They are called Epsilon, Eta, Theta, Iota and Kappa. WHO has yet to recognize variant C.37 in its categories of concern or interest, which 19 countries have already reported, mainly several from South America.

According to the WHO definition, the variants of interest behave differently from their original reference. Or it could be that this type of variant has produced an epidemic in situations of community transmission or has been detected in different countries.

To prevent the emergence of new variants of the COVID-19 virus, every person can help. It remains essential to curb the spread from its source. Sanitary measures to reduce transmission, such as permanent ventilation, frequent hand washing, wearing a mask or chin strap, maintaining a physical distance from other people, and avoiding crowded areas or closed – continue to help reduce the likelihood of new variants appearing as they make it difficult for the virus to transmit and therefore have less opportunity to mutate, according to the WHO.

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