Wastewater data finds omicron may have been in US as early as Nov. 21
A new CDC study finds that the omicron variant was likely in the U.S. more than a week before the first case was detected.
The first official case was detected on Dec. 1 in California. But a review of the national wastewater surveillance system indicates that the variant could have been present as early as Nov. 21, according to samples collected in New York City.
-ABC News' Arielle Mitropoulos, Sony Salzman