A sign at a vaccination site in Los Angeles reflects the holdup in vaccine distribution as a result of this week's storms. White House officials said Friday that the extreme weather delayed the shipment of some 6 million doses across the country. Frederic J. Brown/AFP via Getty Images hide caption
Nurse Modesta Littleman vaccinates patient Peter Sulewski in late January, on the first day of vaccinations at a clinic run by Health Care for the Homeless in Baltimore. Yuki Noguchi/NPR hide caption
White House Press Secretary Jen Psaki announced on Tuesday that the supply of COVID-19 vaccines going directly to pharmacies will double to 2 million this week. Nam Y. Huh/AP hide caption
A highway on-ramp in Houston is closed due to snow and ice on Monday. Frigid temperatures, icy roads and power outages caused by a major winter storm have interfered with COVID-19 vaccine distribution in Texas and several other states. Chengyue Lao/Xinhua News Agency/Getty Images hide caption
In an NPR/PBS NewsHour/Marist poll, Americans view President Trump as either below average or one of the worst U.S. presidents, while incoming President-elect Joe Biden gets better reviews. Jim Watson/AFP via Getty Images hide caption
The incoming Biden administration has plans to speed up distribution of COVID-19 vaccines, by not holding doses in reserve. Paul Sancya/AP hide caption
Gene Bracegirdle is relieved to get his first dose of the vaccine recently in rural Colorado. Matt Bloom/KUNC hide caption
An American flag with an image of a Native American on it in To'Hajiilee Indian Reservation in New Mexico. In California, a vaccine allocation committee is considering taking historical injustice into account in advance of a statewide rollout. Sam Wasson/Getty Images hide caption
Two shipping containers holding the first doses of the Pfizer and BioNTech COVID-19 vaccine arrived at the UPS Worldport in Louisville, Ky., on Sunday. Michael Clevenger/Getty Images hide caption
While coronavirus vaccine trials are ongoing and a U.S. vaccine has yet to be approved, state health officials are planning ahead for how to eventually immunize a large swath of the population. Chandan Khanna/AFP via Getty Images hide caption
Nurse Kathe Olmstead (right) gives volunteer Melissa Harting an injection in a study of a possible COVID-19 vaccine developed by the National Institutes of Health and Moderna Inc. Hans Pennink/AP hide caption