Moderna's COVID-19 vaccine received emergency use authorization from the FDA Dec. 18, making it the second vaccine approved in the U.S.
Pfizer and BioNTech's vaccine won emergency approval Dec. 11.
The federal government will distribute about 5.9 million doses of Moderna's vaccine nationwide starting Dec. 20, with the first deliveries slated for Dec. 21.
Unlike Pfizer's vaccine, Moderna's does not need to be stored at extremely cold temperatures and can be shipped in smaller batches. Therefore, many states are planning to give their allotment to rural hospitals, local health departments and community health centers that were not prioritized on distribution lists for Pfizer's vaccine, reports The New York Times.
Federal officials have reserved another 5.9 million doses of Moderna's vaccine to ship four weeks after the first. The government will also stockpile more than 500,000 doses in case issues arise with the initial shipments, according to the Times. States will learn how many doses they'll receive in the second round of shipments next week.
Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, praised the accelerated development process for both vaccines and called the authorizations "an historic moment" in a Dec. 18 interview with the Times.
Both Moderna and Pfizer's vaccines require two doses and proved up to 95 percent effective in protecting against COVID-19 in late-stage clinical trials.