According to the Nowcast website from the Centers for Disease Control and Prevention (CDC), the omicron variant now makes up a majority of COVID-19 cases in the United States, at 73.2 percent.
Just last week the variant mix was 87% Delta and 12.6% Omicron. The current mix report 73.2% is from Omicron, December 12 - December 18.
Nowcast is a model that estimates more recent proportions of circulating variants and enables timely public health action. CDC is providing weekly Nowcast estimates which will be updated every week on Tuesday.
The Omicron variant likely will spread more easily than the original SARS-CoV-2 virus and how easily Omicron spreads compared to Delta remains unknown. CDC expects that anyone with Omicron infection can spread the virus to others, even if they are vaccinated or don’t have symptoms.
Current vaccines are expected to protect against severe illness, hospitalizations, and deaths due to infection with the Omicron variant. However, breakthrough infections in people who are fully vaccinated are likely to occur. With other variants, like Delta, vaccines have remained effective at preventing severe illness, hospitalizations, and death. The recent emergence of Omicron further emphasizes the importance of vaccination and boosters.
CDC continues to recommend wearing a mask in public indoor settings in areas of substantial or high community transmission, regardless of vaccination status.