CDC: Omicron made up 95% of all COVID-19 cases during the last week of December

The Centers for Disease Control and Prevention now says that the omicron variant is estimated to make up 95% of all COVID-19 cases in the U.S. for the week ending Jan. 1. This is an increase from the week ending Dec. 25, when omicron was estimated to make up 77% of all cases. This is not an exact figure but is an estimate based on the thousands of genomic sequences analyzed every week by the CDC.