The World Health Organization is working with researchers around the globe to better understand the new coronavirus variant after health experts in South Africa, where omicron was first detected, said it appeared to cause only mild symptoms.

There’s no information to suggest that symptoms associated with omicron differ from those caused by other variants, the Geneva-based WHO cautioned Sunday. Some of the earliest reported infections occurred among college students who are more likely to experience less severe illness from COVID-19, and understanding the level of severity of the new strain "will take days to several weeks,” the WHO said.

"We don’t have enough data to determine vaccine effectiveness against omicron or disease severity, so any claims about either at this stage are not evidence-based,” said Raina MacIntyre, professor of global biosecurity at the University of New South Wales in Sydney. "So far, the virus has not mutated to become less severe — in fact the opposite.”