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The study has not peer reviewed, so it has not been scrutinized for inaccuracies or context by specialists.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

Nine percent of Americans -- 28.9 million people – have received one or more vaccine doses, according to a report from the Department of Health and Human Services.

Two percent of Americans -- 7.5 million people -- have received two doses, the report said.

Deaths are down 4% since the peak on Jan. 13, while hospital admissions have decreased 37% since the Jan. 9 peak, the report said.

ABC News’ Josh Margolin and Brian Hartman contributed to this report.

There were 111,896 new cases of COVID-19 confirmed in the United States on Sunday, according to a real-time count kept by Johns Hopkins University.

Sunday's case count is the lowest the country has recorded since Dec. 25 and is also far less than the all-time high of 300,282 newly confirmed infections on Jan. 2, Johns Hopkins data shows.

An additional 1,794 fatalities from COVID-19 were registered nationwide on Sunday, down from a peak of 4,466 new deaths on Jan. 12, according to Johns Hopkins data.

COVID-19 data may be skewed due to possible lags in reporting over the Martin Luther King Jr. Day holiday weekend.

A total of 26,187,424 people in the U.S. have been diagnosed with COVID-19 since the pandemic began, and at least 441,331 have died, according to Johns Hopkins data. The cases include people from all 50 U.S. states, Washington, D.C., and other U.S. territories as well as repatriated citizens.

Much of the country was under lockdown by the end of March as the first wave of pandemic hit. By May 20, all U.S. states had begun lifting stay-at-home orders and other restrictions put in place to curb the spread of the novel coronavirus. The day-to-day increase in the country's cases then hovered around 20,000 for a couple of weeks before shooting back up over the summer.

The numbers lingered around 40,000 to 50,000 from mid-August through early October before surging again to record levels, crossing 100,000 for the first time on Nov. 4, then reaching 200,000 on Nov. 27 before topping 300,000 on Jan. 2.

So far, the U.S. Food and Drug Administration has authorized two COVID-19 vaccines for emergency use -- one developed by U.S. pharmaceutical giant Pfizer and its German partner BioNTech, and another developed by American biotechnology company Moderna and the National Institute of Allergy and Infectious Diseases. More than 32 million vaccine doses have been administered nationwide, according to the latest data from the Centers for Disease Control and Prevention.