The World Health Organization (WHO) said on Tuesday that the Omicron coronavirus variant has a substantial growth advantage and is rapidly replacing other variants. 

"The current global epidemiology of SARS-CoV-2 (virus) is characterized by the emergence of Omicron variant, declining prevalence of the Delta variant, and very low level circulation of Alpha, Beta and Gamma variants," the WHO said in its latest weekly report on COVID-19.

In the week ending January 9, global new cases increased by 55 percent compared to the previous week, the WHO report said. 

All regions, except for Africa, saw an increase in the incidence of weekly cases, while Southeast Asia reported the largest increase in new cases with a 418-percent rise.