About 6.4 million doses of the COVID-19 vaccine from Pfizer (NYSE:PFE) and its partner BioNTech (NSDQ:BNTX) will ship to U.S. states in mid-December, as long as the vaccine soon receives an FDA EUA.

There are also plans to quickly distribute vaccine from rival COVID-19 vaccine developer Moderna (NSDQ:MRNA), which could soon apply for an EUA, officials at the federal government’s Operation Warp Speed said yesterday. Gen. Gustave Perna, the COO of Operation Warp Speed, said he was confident that the U.S. would reach its goal of distributing 40 million doses by the end of the year.

Officials in each state will decide who will get vaccine doses first, though HHS Secretary Alex Azar suggested that healthcare workers, nursing home residents and others who are vulnerable will likely be first in line.

“The American people can be confident that help and hope are on the way,” Azar said during an Operation Warp Speed briefing.

Gen. Gustave Perna, the COO of Operation Warp Speed, said states and other jurisdictions received notices of upcoming vaccine allocations on Friday so that they can plan, and Pfizer has been running dry rehearsals of distribution efforts.

Pfizer has said that it anticipates that it could produce up to 100 million doses in the remainder of 2020 and an additional 1.3 billion next year.

The Phase 3 clinical study of the Pfizer and BioNTech vaccine found a 95% efficacy rate — in line with the preliminary results from Moderna. Pfizer’s BNT162b2 vaccine candidate also appears to have a lower adverse event rate than Moderna’s mRNA-1273 vaccine.

Moderna seems to have the upper hand in terms of its vaccines’ storage requirements, however. The vaccine candidate is stable for 30 days between 2° and 8° C. Pfizer currently specifies that its vaccine candidate should be stored at –70° C.

The Pfizer vaccine in its storage containers lasts for only 20 days, so state governments have been practicing how to deliver vaccine at a fast enough pace that none of the Pfizer vaccine will be wasted.

AstraZeneca (NYSE:AZN) has announced that one of its COVID-19 vaccine candidate dosing regimens is up to 90% effective in preventing COVID-19; HHS has an order for 300 million doses of the AstraZeneca vaccine.