A COVID-19 vaccine created by AstraZeneca and the University of Oxford has been approved for emergency use in the United Kingdom.

Roll out will begin Jan 4, Health Secretary Matt Hancock said.

The U.K. Department of Health and Social care announced that it has accepted the recommendation from the Medicines and Healthcare products Regulatory Agency (MHRA) to authorize the vaccine for use.

"This follows rigorous clinical trials and a thorough analysis of the data by experts at the MHRA, which has concluded that the vaccine has met its strict standards of safety, quality and effectiveness," the Department of Health and Social care said in a press release.

It is the second vaccine approved for use in the U.K. following the rollout of the Pfizer/BioNTech vaccine.

The National Health Service will prioritize giving the first doses of the newly approved vaccine to those in the most high-risk groups.

The vaccine will be given in two doses, with four to 12 weeks between doses, the U.K.-based pharmaceutical company said.

COVID-19 hospitalizations have hit a record high in the U.S.

There are 124,686 people currently hospitalized, according to the COVID Tracking Project.

There were also 194,512 new cases and 3,283 deaths reported on Tuesday, though the tracker noted that there are delays in both figures due to the holidays.

"Current hospitalizations remains our most stable state-reported metric during holiday disruptions, and it will be our best guide to reality until states work through all Christmas + New Year’s backlogs," it said.

The U.S. Dept. of Health and Human Services revised its earlier expectation that 20 million coronavirus vaccine doses would be administered by Christmas, the agency said in a statement Tuesday.

It now expects to hit 20 million vaccines into the first week of January, an Operation Warp Speed spokesperson said in a statement.

"These doses are being distributed at states’ direction to the American people as quickly as they are available and releasable," OWS spokesman Michael Pratt said in a statement.

Pratt added that the lag in reporting vaccination doses administered is expected.

-ABC News' Anne Flaherty contributed to this report.

Texas broke records for daily cases and hospitalizations on Tuesday, according to the state's health department.

The state recorded 26,990 news cases and 49 new deaths, the health department said. There were 11,775 hospitalized statewide and Texas had 653 available intensive care unit beds, according to the health data.

The new cases were announced on the same day it was revealed that only 163,700 of the 611,850 vaccine doses received by the state have been administered so far. Gov. Greg Abbott previously said he expected to receive 1.4 million doses by the end of the year.

Texas Health Commissioner Dr. John Hellerstedt said in a statement that no vaccine should be kept in reserve.

"All providers that have received COVID-19 vaccine must immediately vaccinate healthcare workers, Texans over the age of 65, and people with medical conditions that put them at a greater risk of severe disease or death from COVID-19," he said in a statement.

-ABC News' Gina Sunseri contributed to this report.

Huntington Hospital in Pasadena, California, released a patient information sheet documenting how they will use their medical resources should they see a shortage due to an overwhelming number of new patients following the holidays.

"We are not currently in this situation, but could be based on ongoing increase in hospitalized COVID-19 patients," they told ABC News, adding that on Sunday they had their highest number of patients (189) in a single day.

In the letter, the hospital explained that due to rising cases of COVID-19 in the community, they may experience limited resources. These include life support machines (like a ventilator or breathing machine), intensive care unit (ICU) beds and healthy medical staff to care for patients.

If there is a shortage of resources, a team of medical professionals will review the cases of all patients who are critically ill to determine how these resources should be shared throughout the hospital.

"If a patient becomes extremely sick and very unlikely to survive his/her illness (even with life-saving treatment) – limited medical resources may go to treat other patients who are more likely to survive," the letter reads.

"Our community is facing a public health emergency that has severely constricted the medical resources available to patients in the Los Angeles County and greater Southern California region. Hospitals such as ours are working hard to meet the dramatic rise in needed care during this COVID-19 surge. We expect to face additional challenges moving forward after the holiday season," the hospital said in a statement.

ABC News' Abigail Shalawylo contributed to this report.