The omicron variant of the coronavirus now accounts for nearly three quarters of all new infections in the U.S., according to the latest data from the Centers for Disease Control and Prevention.
Estimates for the week ending Dec. 18 indicate that omicron is behind 73.2% of total new cases, compared to 26.6% for the Delta variant, the data shows.
In the week before, only 12.6% of positive tests were a result of the omicron variant, as Delta, at 87%, remained the most infectious variant in the U.S., according to the CDC.
Meanwhile, an unvaccinated Texas man in his 50s with underlying health conditions is believed to have been the first American to die from the omicron variant.
Omicron has been reported in nearly every state, and it accounts for about 90% of new cases in some areas of the country, such as New York, the Southeast, and the Pacific Northwest.
The omicron variant was first discovered in South Africa less than a month ago and the World Health Organization declared it a "variant of concern" on Nov. 26.
It's still unclear whether omicron causes more or less severe COVID-19 symptoms, but the CDC says "it likely will spread more easily than" previous variants.
This afternoon, President Biden is set to address the nation to lay out his administration’s latest strategy in combating the coronavirus.
Fox News’ Paul Best contributed to this report.