Omicron likely to become dominant Covid-19 variant in US: Fauci

"Omicron is going to be a challenge because it spreads very rapidly, and the vaccines that we use -- the regular two-dose mRNA -- don't do very well against infection itself,"  he said on Tuesday in an interview with CNN. 

In South Africa, where the Omicron variant was first identified, while there is almost a vertical spike of infection, the country is not seeing severe hospitalisations, according to Fauci, Director of the US National Institute of Allergy and Infectious Diseases. 

The Omicron variant, which is possibly more contagious than the Delta variant, had been found in at least 31 US states as of Monday, since the first case in the country was detected in California on December 1, Xinhua news agency reported.