BA.2 should be considered a variant of concern and remain classified as omicron, says WHO

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This is what we know about BA.2, a new subvariant of omicron 0:41

(CNN) — The BA.2 subvariant should not be reclassified as a separate Greek-letter named coronavirus variant, but should remain part of omicron and be monitored as a variant of concern, the World Health Organization (WHO) said in a statement. release this Tuesday.

The WHO Technical Advisory Group on SARS-CoV2 virus evolution (TAG-VE) met on Monday to review the latest science on BA.1 and BA.2.

The WHO experts received information from Japanese scientists who recently conducted laboratory and animal studies with BA.2 and concluded that it may cause more severe disease than the original omicron variant.

They also considered real-world data on clinical severity in South Africa, the UK, and Denmark, where immunity to infection and vaccination is high. The panel said that no difference in severity between BA.1 and BA.2 was reported in real-world data.

A dose of the Moderna vaccine against covid-19 is prepared to be administered at Babington Hospital in Belper on December 16, 2021 as the UK stepped up the country’s booster campaign to combat the spread of the omicron variant. (OLI SCARFF/AFP via Getty Images)

The omicron variant currently dominates the transmission of covid-19 worldwide. The omicron virus family consists of several sublineages, including BA.1, BA.1.1, BA.2, and BA.3.

BA.2 is about 30% more transmissible than the original omicron strain, according to studies from the UK and Denmark. It is now the dominant cause of Covid-19 infections in at least 10 countries, including India and Denmark.

Genetically, BA.2 is very different from the first omicron virus that swept the world, BA.1. Dozens of genetic changes separate the two, making them as different as the alpha, beta, gamma, and delta variants were from each other. That led some scientists to ask the WHO to separate BA.2 from the omicron family and give it a Greek letter name.

The WHO says it will continue to closely monitor the BA.2 lineage.