COVID-19 updates: US has 1st day since November with fewer than 100K new cases

The battles over in-person learning between teachers and the school districts in Chicago and San Francisco may temporarily be over.

Chicago Mayor Lori Lightfoot announced in a press conference Sunday that "at long last" a tentative agreement has been reached. Students will return to the classroom in stages, with pre-K students starting on Feb. 11, kindergarten through fifth grades on March 1 and sixth through eighth grades on March 8.

It is unclear when high school students will be slated to return to in-person learning. Public schools in Chicago had been fully remote since the pandemic began last spring.

In San Francisco, teachers unions have agreed to return to in-person learning when the city progresses to the red tier, California’s second-least most restrictive level. The city is currently in the purple tier, the state's most restrictive mode in the reopening plan.

ABC News’ Meredith Deliso, Joshua Hoyos and Matthew Fuhrman contributed to this report.

The number of cases, hospitalizations and deaths are continuing to decline nationwide, according to a new report by the U.S. Department of Health and Human Services.

There has been a four-week downward trend of reported COVID-19 cases – resulting in a 50% decline since the peak on Jan. 8.

However, the rates of adult occupancy in intensive care units remain high in several states, the report found.

So far, 39,037,964 vaccine doses have been administered, with 9% of the population (30.3 million people) having received one or more doses and 3% of the population (8.3 million people) having received two doses.

Since President Joe Biden was sworn in on Jan. 20, 22,512,683 doses have been administered toward his 100 million goal.

ABC News’ Josh Margolin and Arielle Mitropoulos contributed to this report.

Cases of the more contagious U.K. variant of the COVID-19 virus is spreading rapidly through the U.S., as much as doubling every 10 days, a new study suggests.

The study has not peer reviewed, so it has not been scrutinized for inaccuracies or context by specialists.

It is still not known whether the U.K. variant is more virulent or deadly, but it is more transmissible. The Centers for Disease Control and Prevention warned last month that the U.K. variant could become predominant in the U.S. by March if spread the way it did in the U.K.

Vaccines don’t seem to be strongly impacted by the U.K. variant, but scientists are concerned about the efficacy of the vaccines against the South African variant.

-ABC News’ Eric Strauss

A second storm bringing heavy snow to the Northeast has shut down vaccination sites in at least two states.

New York Gov. Andrew Cuomo and New Jersey Gov. Phil Murphy both announced that appointments for Sunday would be rescheduled due to the inclement weather.

Mass vaccination sites located indoors, such as the newly opened Yankee Stadium, will continue as scheduled as they have the infrastructure and equipment in place to ensure people can safely enter and exit the location, according to ABC New York station WABC.