Covid-19: WHO sounds warning over fast-spreading Omicron variant

Says Omicron is evading some immune responses; China must share more data on virus origins

The Omicron variant of the coronavirus is spreading faster than the Delta variant and is causing infections in people already vaccinated or who have recovered from the COVID-19 disease, the head of the World Health Organization (WHO) said on Monday.

WHO chief scientist Soumya Swaminathan added it would be "unwise" to conclude from early evidence that Omicron was a milder variant that previous ones.

"... with the numbers going up, all health systems are going to be under strain," Soumya Swaminathan told Geneva-based journalists.

The variant is successfully evading some immune responses, she said, meaning that the booster programmes being rolled out in