COVID: Omicron sub-variant not more severe than original, says WHO

The World Health Organisation (WHO) says the BA.2 variant of the Omicron coronavirus strain is not more severe than the original BA.1 strain.

Maria Van Kerkhove, a senior WHO official, was reporting the findings of a committee of experts tracking the evolution of the virus during an online question and answer session on Tuesday.

Omicron has four lineages (variants) — BA.1, BA.1.1, BA.2 and BA.3 — with BA.1 being the original Omicron variant and accounting for the vast majority of Omicron cases.

Kerkhove said based on a sample of people from various countries “we are not seeing a difference in severity of BA.1 compared to BA.2”.

“So this is a similar level of severity as it relates to risk of hospitalisation. And this is really important, because in many countries they’ve had a substantial amount of circulation, both of BA.1 and BA.2,” she said.

In a subsequent statement on Tuesday, the WHO said as part of its on-going work to track variants, its technical advisory group on SARS-CoV-2 virus evolution (TAG-VE) met to discuss the latest evidence on the Omicron variant of concern, including its sublineages BA.1 and BA.2.

It said based on available data of transmission, severity, reinfection, diagnostics, therapeutics and impacts of vaccines, the group reinforced that the “BA.2 sublineage should continue to be considered a variant of concern and that it should remain classified as Omicron”.

“The group emphasized that BA.2 should continue to be monitored as a distinct sublineage of Omicron by public health authorities,” the statement reads.

“WHO will continue to closely monitor the BA.2 lineage as part of Omicron and requests countries to continue to be vigilant, to monitor and report sequences, as well as to conduct independent and comparative analyses of the different Omicron sublineages.”