Based on a sample of people from various countries, "we are not seeing a difference in the severity of BA.1 compared to BA.2," Maria Van Kerkhove, a senior WHO official, said in an online question and answer session.
"So this is a similar level of severity as it relates to the risk of hospitalization. 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.
Van Kerkhove, who leads the technical side of the WHO's COVID-19 response team, was reporting the findings of a committee of experts tracking the evolution of the virus.
Their conclusions will come as a relief to countries such as Denmark, where the BA.2 variant of omicron has circulated widely.
The WHO said in a statement that initial data suggests the new BA.2 variant "appears inherently more transmissible than BA.1," and that further studies are ongoing to discover why this is the case.
"However the global circulation of all variants is reportedly declining," it added.
Coronavirus has killed more than 5.8 million people worldwide, according to an Agence France-Presse (AFP) tally compiled from official sources on Tuesday.
Taking into account excess mortality linked to COVID-19, the WHO estimates the correct death toll could be two to three times higher.
