Coronavirus updates: US reports nearly 300,000 new cases in all-time high

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.

Kentucky Gov. Andy Beshear spoke out Monday after Walgreens stores in Louisville and Lexington, Kentucky, gave COVID-19 vaccines to members of the general public. 

Beshear said at a press conference that last week, the pharmacies were left with extra doses of the vaccine after administering it to long-term care facilities, so, they offered the leftover doses to average citizens. This, the governor said, does not follow government protocol, as the vaccine is not yet being given to the general public.

"I don't think that this was intentional, and we have to understand that in an undertaking this massive that mistakes are going to happen," Beshear said. "I believe that here a mistake happened in the thawing, but the reaction wasn't what it should've been."

In a statement, Walgreens said that per the Centers for Disease Control and Prevention's guidance, Pfizer’s COVID-19 vaccine can be at refrigerated temperatures for only five days, so, to avoid wasting doses of the valuable vaccine after giving it to at-risk adults in long-term care facilities, they used the leftover doses they had on residents. 

The doses were offered to local first responders, Walgreens pharmacy and store team members and residents of the community, many of whom were over age 65, Walgreens said.

"These measures were taken to ensure every dose of a limited vaccine supply was used to protect patients and communities," the company added. "We will utilize excess vaccine inventory in priority patient populations and continue to work closely with state and federal health agencies in our efforts to vaccinate residents in long-term care facilities and ensure requested doses meet their needs."