December has been the worst month on record for cases, hospitalizations, and deaths. Even with delays in reporting because of the holidays, hundreds of thousands of Americans are still testing positive for the virus every day.

The U.S. has logged more than 5.6 million cases in the first 28 days of December -- more than any month on record, according to ABC News’ analysis of data compiled by the COVID Tracking Project.

According to the CDC, California currently has the highest average of daily cases per 100,000 people in the last seven days, followed by Tennessee, Oklahoma and Arizona.

Across the U.S., 121,235 people are currently hospitalized with COVID-19 -- setting a new record high since the pandemic began. That total is double the previous hospitalization peaks from April and July.

ABC News’ Arielle Mitropoulos contributed to this report.

Vice President-elect Kamala Harris received her first dose of the Moderna vaccine on Tuesday morning at United Medical Center in Washington, D.C.

"That was easy!" she said after. "I barely felt it."

"I want to encourage everyone to get the vaccine," Harris said. "It is literally about saving lives. I trust the scientists, and it is the scientists who created and approved this vaccine."

"Right in your community is where you can take the vaccine," Harris said. "Where you will receive the vaccine by folks you may know, folks who otherwise are working in the same hospital where your children were born, folks who are working in the same hospital where an elderly relative received the kind of care that they needed. So I want to remind people that they have trusted sources of health, and that's where they will be able to go to get the vaccine, so I encourage them to do that."

Harris’ husband, Doug Emhoff, also received the vaccine.

Staff and residents of Holyoke Soldiers' Home in Holyoke, Massachusetts, started receiving COVID-19 vaccinations Tuesday morning.

Staff looked on as the first person -- 78-year-old man U.S. Air Force Veteran Robert Aucoin -- was inoculated.

The long-term care facility has suffered one of the worst coronavirus outbreaks in the country. In the spring, 76 veterans who lived at the home died of the virus. A resident who had been living in an off-site nursing facility since April died earlier this month.

Two former top administrators pleaded not guilty to criminal negligence charges connected to the residents' deaths, WCVB reported.

U.S. states have begun vaccinating patients at long-term care facilities in an effort to keep the most vulnerable Americans safe from the virus. The government's goal is to have 20 million Americans vaccinated by the end of the year.

The TSA screened 1,111,751 travelers at checkpoints across the U.S. on Monday. This marked the seventh day within the last 11 days that more than 1 million people were traveling.

ABC News’ Sam Sweeney contributed to this report.

New York State Police will refer ParCare Community Health Network to the New York Attorney General’s office for allegedly misappropriating the Moderna vaccine, Gov. Andrew Cuomo said Monday.

State Health Commissioner Howard Zucker said the Orange County-based health care provider obtained the vaccine under false pretenses, moved it to Brooklyn, and gave it to people who weren't on the priority list. While ParCare is the only organization currently under criminal investigation, the governor said recipients of the vaccine who violated the state's distribution plan could also face charges.

"Whenever you have a valuable commodity that is being dispensed you should expect fraud," Cuomo said.

Under New York's current plan for "1A" distribution, only medical workers, first responders and nursing home staff members are allowed to receive the coronavirus vaccine. Other groups will follow in future rounds.

"We take this very seriously," Zucker said in a statement last week. "Anyone found to have knowingly participated in this scheme will be held accountable to the fullest extent of the law."

New York State Police and other investigators were at the ParCare location in Borough Park on Saturday night.

A spokesman for ParCare told ABC News Sunday evening that it is cooperating with the state investigation and will return its unused vials. ParCare received 2,300 doses of the Moderna vaccine, and 869 of those doses have already been administered, according to the spokesperson.

"ParCare followed all NYS DOH procedures for obtaining the Moderna vaccine and was approved by NYS DOH for distribution and by CDC as a network site. As a result, we have properly received the vaccines and have provided the documentation regarding the proper receipt of the vaccines to the NYS DOH," the spokesperson told ABC News.

With regards to the patients who received their first shot, ParCare said it will be "working with the state to ensure that we provide the second dose for our patients."

-ABC News' Ivan Pereira, Sasha Pezenik and Aaron Katersky contributed to this report.