“There are many of these parties that have 30, 40, 50 people in which you do not know the vaccination status of individuals. Those are the kind of functions in the context of Omicron that you do not want to go to,” Fauci said at a White House briefing.

The seven-day average of Covid-19 cases in the US increased by 25% from the previous week to about 149,300 cases per day, US Centers for Disease Control and Prevention Director Rochelle Walensky said.

The Omicron variant of the coronavirus represents approximately 73% of cases across the country and is as high as 90% of cases in some areas, such as the eastern Atlantic states, parts of the Midwest, South, and northern Pacific states, Walensky told reporters at the same briefing.

“This increase in Omicron proportion is what we anticipated and what we have been preparing for,” she said.