FILE - In this Nov. 13, 2020, file photo Army Gen. Gustave Perna, who is leading Operation Warp Speed, speaks during at an event in the Rose Garden of the White House in Washington. The Army general in charge of getting COVID-19 vaccines across the United States apologized on Saturday, Dec. 19, for “miscommunication” with states over the number of doses to be delivered in the early stages of distribution. "I failed. I'm adjusting. I am fixing and we will move forward from there," Perna told reporters in telephone briefing. (AP Photo/Evan Vucci, File)

Nurse Cathy Pitts prepares a COVID-19 vaccine at Ascension Saint Thomas Hospital West in Nashville, Tenn., Thursday, Dec. 17, 2020. (Andrew Nelles/The Tennessean via AP)

FILE - In this March 18, 2020, file photo, Thomas Waerner, of Norway, arrives in Nome, Alaska, to win the Iditarod Trail Sled Dog Race. The 2021 Iditarod Trail Sled Dog Race will be about 140 miles shorter than normal as a result of complications stemming from the coronavirus pandemic, race officials announced Friday, Dec. 18, 2020. The teams will no longer embark on a 1,000-mile (1,609-kilometer) journey to Nome but instead will take a roughly 860-mile (1,384-kilometer) loop that starts and ends in Willow. (Marc Lester/Anchorage Daily News via AP)

Arizona Air National Guard medic Will Smith, right, receives one of the first doses of the Pfizer-BioNTech vaccine for COVID-19 at the Arizona Department of Health Services State Laboratory from nurse Machrina Leach, Wednesday, Dec. 16, 2020, in Phoenix. The Pfizer vaccine was almost 95 percent effective at preventing patients from contracting COVID-19 and caused no major side effects in a trial of nearly 44,000 people. (AP Photo/Ross D. Franklin)

Respiratory therapist Leigha McDaniels receives a COVID-19 vaccination, Monday, Dec. 14, 2020, at Mercy Hospital St. Louis, in St. Louis. McDaniels admits at first she had concerns with getting the vaccination but talked about her concerns with her co-workers. "I am glad I decided to get it. I don't want to get COVID, I have seen what it can do to patients," said McDaniels. (Laurie Skrivan/St. Louis Post-Dispatch via AP)

People who were just tested for COVID-19 wait in line to make payment for the test at a private laboratory in Johannesburg, South Africa, Saturday Dec. 19, 2020. South Africa is bracing for its second wave, as many people will travel across provinces for vacations and visiting their families. (AP Photo/Jerome Delay)

FILE - In this Dec. 16, 2020, file photo, Jessica Daniels, right, immunization program coordinator for Legacy Emanuel, first-bumps Kelley Callais after Callais administered her COVID-19 vaccination shot at at Legacy Emanuel Medical Center in Portland, Ore. Officials in Oregon learned early in the pandemic that they needed to look locally for connections to help them source increasingly scarce personal protective equipment. (Dave Killen/The Oregonian via AP)

FILE - In this Dec. 17, 2020, file photo, a woman waits at a bus stop where pandemic public service signs are displayed in Chicago. (AP Photo/Charles Rex Arbogast, File)

People queue in line to wait for coronavirus testing while maintaining social distancing at Seoul Plaza in Seoul, South Korea, Friday, Dec. 18, 2020. (AP Photo/Lee Jin-man)

People wait to board trains with destinations including the Midlands, north of England and Scotland at Euston railway station in London, Friday, Dec. 18, 2020. The British government plans to relax restrictions on socializing and travel for five days before and after Christmas. With infections rising in the U.K., which has Europe's second-highest coronavirus death toll after Italy, there are concerns about a possible fresh surge of cases and deaths after the holidays. (AP Photo/Matt Dunham)

American flags fly around the Washington Monument Friday, Dec. 18, 2020, in Washington. The Trump administration has closed the Washington Monument because of a recent visit by Interior Secretary David Bernhardt, who tested positive this week for the coronavirus. Interior spokesman Nicholas Goodwin says a couple monument workers were quarantining as a result of Bernhardt's visit, forcing a staffing shortage and the monument's closure. (AP Photo/Manuel Balce Ceneta)

Britain's Prime Minister Boris Johnson speaks during a news conference in response to the ongoing situation with the coronavirus (COVID-19) pandemic, inside 10 Downing Street, London, Saturday, Dec. 19, 2020. Johnson says Christmas gatherings can’t go ahead and non-essential shops must close in London and much of southern England as he imposed a new, higher level of coronavirus restrictions to curb rapidly spreading infections. (Toby Melville/Pool Photo via AP)

Surfers ride a wave past a sign at a beach in Sydney, Australia, Saturday, Dec. 19, 2020. Sydney's northern beaches will enter a lockdown similar to the one imposed during the start of the COVID-19 pandemic in March as a cluster of cases in the area increased to more than 40. (AP Photo/Mark Baker)

Christmas cards and costumes are displayed in the window at Mid Central Printing & Mailing store in Wilmette, Ill., Friday, Dec. 18, 2020. Isolated by the coronavirus pandemic, Americans are sending more Christmas and holiday cards to stay in touch this year. (AP Photo/Nam Y. Huh)

A skyscraper, known as the Tower of Piraeus, is illuminated for Christmas, at Piraeus port town, near Athens, Greece, on Saturday, Dec. 19, 2020. Despite six weeks of lockdown measures, coronavirus deaths and infections remain high, piling pressure on the country's health system. (AP Photo/Yorgos Karahalis)

A boy skates in front of Christmas decoration outside the Municipal Theatre at Piraeus port town, near Athens, Greece, on Saturday, Dec. 19, 2020. Despite six weeks of lockdown measures, coronavirus deaths and infections remain high, piling pressure on the country's health system. (AP Photo/Yorgos Karahalis)

A lone man who was just tested for COVID-19 waits in line to make payment for the test at a private laboratory in Johannesburg, South Africa, Saturday Dec. 19, 2020. South Africa is bracing for its second wave, as many people will travel across provinces for vacations and visiting their families. (AP Photo/Jerome Delay)