Omicron is now the dominant strain of the coronavirus in the United States, making up 73 percent of new infections in the country last week, federal health officials said Monday. The Associated Press reported that the Omicron variant accounts for an even higher level of cases in certain parts of the U.S., constituting roughly 90 percent of new infections in the New York area, the Southeast, the industrial Midwest, and the Pacific Northwest. As recently as late last month, more than 99.5 percent of new cases were the Delta variant, according to Centers for Disease Control and Prevention data. That same data is now showing nearly a six-fold increase in Omicron infections in the span of a single week. “All of us have a date with Omicron,” a senior scholar at the Johns Hopkins Center for Health Security said. “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.”