The omicron coronavirus variant has quickly become the dominant strain in the U.S., accounting for 73.2 percent of new infections for the week ending Dec. 18, genomic surveillance data from the CDC shows.
That's up from just 13 percent Dec. 11, the updated data reflects, underlining the strain's increased transmissibility. Before the data was updated on Dec. 20, the strain was believed to represent 3 percent of cases Dec. 14.
The updated data shows that in many parts of the country, omicron now makes up at least 90 percent of cases, and that delta — which had been the dominant strain since July — now makes up about 27 percent of cases nationwide.
Health officials from the Harris County Public Health department in Texas also recorded what is believed to be the first death in the nation related to omicron on Dec. 20, ABC News reported. The patient was unvaccinated and between the ages of 50 and 60. He had a prior infection and "was at higher risk of COVID-19 due to his unvaccinated status and had underlying health conditions," health officials said in a statement.