Omicron now accounts for more than 70% of COVID cases in the U.S., the CDC said Monday.

The rates of hospitalization and death do not seem to be rising along with the number of omicron infections — unlike the trend with the original coronavirus and with the delta variant.

Omicron’s share of infections multiplied nearly sixfold in just one week, the CDC said. In the New York area, it’s responsible for about 90% of infections, as well as in the Southeast, the industrial Midwest and the Pacific Northwest.

“It is very much here,” Dr. Jennifer Lighter, hospital epidemiologist and pediatric infectious diseases specialist at NYU Hassenfeld Children’s Hospital, told the Daily News. “It’s way more prevalent than people realize. The huge spike we’re getting this week is not more delta. It is omicron. It’s the predominant strain right now.”

Omicron is most likely responsible for breakthrough infections being reported among those who’ve been vaccinated and gotten booster shots, she said.

“It causes more breakthroughs than delta,” Lighter told The News. “Certainly, if they’re vaccinated and they get a breakthrough, it’s probably omicron. It’s mostly going to be omicron in the next week or two.”

Delta had been the main driver of infections in the U.S. before this, starting in June, and just three weeks ago that variant accounted for more than 99.5% of coronavirus cases in this country.

Omicron has been on the world’s radar just under a month, when it was first identified in South Africa, and has only been in the World Health Organization’s sights as a “variant of concern” since Nov. 26. Omicron has since been detected in 90 countries and all but three U.S. continental states.

“All of us have a date with omicron,” Dr. Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security, told AP. “If you’re going to interact with society, if you’re going to have any type of life, omicron will be something you encounter, and the best way you can encounter this is to be fully vaccinated.”