Omicron variant spreads worldwide as scientists race to find answers

South African doctor says Omicron patients have 'very mild' symptoms; Israel announces it is barring foreigners for two weeks.

The Omicron coronavirus variant spread around the world on Sunday, with new cases found in the Netherlands, Denmark and Australia even as more countries imposed travel restriction to try to seal themselves off.

The World Health Organization (WHO) said it was not yet clear whether Omicron, first detected in Southern Africa, is more transmissible than other variants, or if it causes more severe disease.

"Preliminary data suggests that there are increasing rates of hospitalization in South Africa, but this may be due to increasing overall numbers of people becoming infected, rather than a result of specific infection," WHO said.

It said understanding the