The omicron variant accounted for 73% of all sequenced Covid-19 cases in the U.S., surging from around 3% last week, according to the latest federal estimates.
The highly mutated coronavirus strain has been detected across the country, the Centers for Disease Control and Prevention said in a model that it updates weekly. The delta variant, which had been the dominant form of the virus in the U.S. last week, has now receded to roughly 27% of sequenced cases.
The sizable increase in omicron’s overall prevalence underscores fears that the rapidly spreading variant could produce a wave of infections that will strain the U.S. health-care system. While there is evidence that omicron doesn’t produce more severe illness than delta, a large surge in infection levels could still swamp hospitals with sick patients.
The jump in omicron was expected and is similar to patterns seen worldwide, the CDC said. In some pockets of the U.S., omicron accounts for nearly all new infections. The variant made up an estimated 92% of cases in New York and New Jersey, the CDC estimate showed, and 96% in Washington state.
The U.S. is urging those who are eligible to get vaccinated and to seek out booster shots to ward off omicron. On Monday, Moderna Inc. said a third dose of their vaccine increased antibody levels against the variant, and Pfizer Inc. and BioNTech SE have said lab studies show that a third dose of their vaccine also helps neutralize omicron.
Other prevention measures such as masking indoors and at-home testing can also help curb transmission of the virus, the CDC said.
The spread of omicron has meanwhile forced many businesses to reconsider return-to-office plans as well as events like investor meetings. Last week, JPMorgan Chase & Co. elected to move its annual health-care conference next month online, and on Monday the World Economic Forum said that its planned meeting next month in Davos, Switzerland was postponed.
