WHO adds two new sub-variants of Omicron to watch list

The tracking of two infections sub-variant The new Omicron BA.4 and BA.5 variants aim to see if these sub-variants are more contagious or dangerous.

WHO has added BA.4 and BA.5, “par” variants of the parent subvariant BA.1 of Omicron, to the list of variants to monitor. WHO has tracked subvariants BA.1 and BA.2, which currently account for the number of new COVID-19 cases globally, as well as subvariants BA.1.1 and BA.3.

The WHO said that “further study of the novel mutations of these subvariants is needed to understand their impact on the virus’ ability to evade the immune system”.

All viruses change over time. However, there are only a few variants that affect the ability to spread or evade immunity acquired through vaccination or infection, or the severity of disease caused by these subvariants. .

Laboratory staff working to sequence the genome of the SARS-CoV-2 virus. (Photo: CBC News)

Eg, sub-variant BA.2 of Omicron (also called “variant”Stealth Omicron“) currently causes close to 94% of sequenced cases. This variant is more contagious than other minor variants, but evidence to date suggests that BA.2 is unlikely to do so. severe illness.

According to WHO, only a few infections with sub-variants BA.4 and BA.5 have been reported to the WHO Global Database (GISAID).

The UK Health Security Agency said last week that the BA.4 sub-variant had been detected in South Africa, Denmark, Botswana and parts of the UK between January 10 and March 30. Meanwhile, all BA.5 sub-variant infections were detected in South Africa.

Botswana Ministry of Health announced on April 11 that the country has detected 4 cases of infection with sub-variants BA.4 and BA.5 in people aged 30-50 years, who are fully vaccinated and show symptoms. light body.

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