The Delta variant has largely replaced the other three variants of concern

The “worrying” variant Delta, present in 185 countries, has largely replaced the three other “worrying” variants, Alpha, Beta and Gamma, which now each represent less than 1% of sequenced cases, the World Organization said on Tuesday. of Health (WHO). All viruses, including the SARS-CoV-2 responsible for Covid-19, mutate over time.

The emergence, at the end of 2020, of variants that presented an increased risk to global public health led the WHO to characterize variants “to be monitored” and others as “of concern”, in order to prioritize surveillance and monitoring activities. global research. “The predominant virus currently circulating is the Delta variant,” said WHO COVID-19 technical team director Maria Van Kerkhove in a question-and-answer session on social media.

A more transmissible virus

The three other worrisome variants – Alpha, Beta and Gamma – each represent less than 1% of the sequences currently available, according to the WHO. “This virus has become stronger, it is more transmissible and it is competing, replacing other viruses that are circulating,” she added, adding that it had been reported in 185 countries.

The WHO has decided to name the variants “to watch” or “of concern” using letters of the Greek alphabet, in order to avoid any stigmatization of a particular country and to allow the general public to pronounce them. names more easily. Currently, the WHO considers four variants to be “of concern”. The organization also considered so far that five other variants (Eta, Iota, Kappa, Lambda and Mu) were “to be continued”. But three of them – Eta, Iota, Kappa – have just been downgraded, announced Maria Van Kerkhove.

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