Boxes containing the Moderna COVID-19 vaccine are prepared to be shipped at the McKesson distribution center in Olive Branch, Mississippi. The vaccine campaign needs further federal support, experts say, to speed the effort.

OLIVE BRANCH, MISSISSIPPI – DECEMBER 20: Boxes containing the Moderna COVID-19 vaccine are prepared to be shipped at the McKesson distribution center in Olive Branch on December 20, 2020 in Olive Branch, Mississippi. The federal government plans to distribute over the coming week a total of 7.9 million doses of vaccines from Moderna and Pfizer Inc. (Photo by Paul Sancya – Pool/Getty Images)