CDC Overestimated Percentage Of Omicron Cases – Delta Still Out There

The Omicron variant of COVID-19 is not as widespread as the Centers for Disease Control and Prevention (CDC) initially led people to believe.

CDC estimates of circulating variants including week of 12/25. Notably week of 12/18 estimate of Omicron revised from ~73% to 22.5% (just a tad different!).

Now saying 58.6% of variants are Omicron nationwide. 1/ pic.twitter.com/duYpLSEXQm

— Jason Gallagher (@JGPharmD) December 28, 2021

The data for the week of Dec. 12 to Dec. 18 was revised when the CDC released new data for the most recent available week, Dec. 19 to Dec. 25. Instead of Omicron becoming dominant between Dec. 12 and Dec. 18, Delta was still the dominant strain at the time, making up 77% of cases.

According to the most recent estimate for the week of Dec. 19 to Dec. 25, Omicron has become dominant. It’s still only making up 58.6% of cases, though, not the 73% that was once reported.

Omicron is most prominent right now in Health and Human Services region 2 (New York, New Jersey, Puerto Rico, and the Virgin Islands) and region 6 (Arkansas, Louisiana, New Mexico, Texas, and Oklahoma). There are two regions where Delta is still the dominant variant: region 1 (Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont) and region 7 (Iowa, Kansas Missouri, and Nebraska).

The new data suggest Omicron may still have more room to spread than previously believed. While the variant is less severe than previous strains of the virus, it is far more contagious and can more easily infect vaccinated or naturally immune individuals.