The average number of deaths per day has remained fairly steady throughout December and into early January at about 1,300, according to a Reuters tally, though deaths typically lag behind cases and hospitalizations.
Omicron is appears to be far more easily transmitted than previous iterations of the virus, though the World Health Organization said on Tuesday that evidence thus far suggests the variant is causing less severe illness.
Nevertheless, public health officials have warned that the sheer volume of Omicron cases threatens to overwhelm hospitals, some of which are already struggling to handle a wave of COVID-19 patients.
Delaware, Illinois, Maryland, Ohio and Washington, DC, have reported record numbers of hospitalized COVID patients in recent days.
The unrelenting surge has prompted more than 3,200 schools to close their buildings this week, according to Burbio, a site that tracks school disruptions. Schools that have remained open are facing staff shortages and renewed concerns about virus spread.
In Boston, where more than 54,000 students returned to class on Tuesday following the holiday break, Superintendent of Schools Brenda Cassellius told reporters there were 1,000 staff members out, including 461 teachers and 52 bus drivers.
"It does make for a difficult start to the day," she said.
In Chicago, the teachers union objected to Monday's return to schools, saying the district needs stricter protocols such as required testing. Teachers were expected to vote on Tuesday on whether they support working remotely starting on Wednesday.
The Biden administration has continued to emphasize widespread vaccinations and boosters as the best way to protect against severe infections.
The US Centers for Disease Control and Prevention on Tuesday recommended shortening the interval between Pfizer-BioNTech's second Covid-19 vaccine dose and the booster shot to five months from six, a day after the Food and Drug Administration made a similar move.