The Omicron Covid-19 variant is now the most dominant strain in the US, accounting for over 73% of new coronavirus cases less than three weeks after the first was reported, according to estimates posted Monday by the US Centers for Disease Control and Prevention. It's been just 20 days since the US detected its first case of Omicron. For the week ending December 18, Omicron accounted for 73.2% of cases, with Delta making up an additional 26.6%.
The week prior, ending December 11, Omicron was estimated at just 12.6% of circulating virus, and in the first week of December, Omicron accounted for about 1% of new cases. Omicron is even more prevalent in certain parts of the country — making up over 95% of circulating virus in parts of the Northwest and Southeast, the data shows. As of Monday, 48 US states have reported cases of Omicron, according to public statements from hospital systems and state officials, as well as Puerto Rico and Washington, DC. The only states that have not reported cases of Omicron are Oklahoma and South Dakota. Dr. Anthony Fauci, the nation's top infectious diseases expert, warned on CNN's "State of the Union" Sunday that Omicron was "going to take over" soon due to its highly contagious nature. The World Health Organization says Omicron cases are doubling every 1.5 to 3 days.