The BA.2 variant of the Omicron coronavirus strain is not more severe than the original, the World Health Organization said on Tuesday.

Based on a sample of people from various countries, "we are not seeing a difference in 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 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.

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.