US has $2B deal with Pfizer for a vaccine

WASHINGTON — The Trump administration Wednesday announced a nearly $2 billion contract with the pharmaceutical giant Pfizer and Biontech, a smaller German biotechnology company, for up to 600 million doses of a coronavirus vaccine — if they develop one.

If such a vaccine proves to be safe and effective in clinical trials, the companies say they could manufacture the first 100 million doses by December.

Under the arrangement, the federal government would obtain the first 100 million doses for $1.95 billion, or about $20 a dose, with the rights to acquire up to 500 million more. Americans would receive the vaccine for free. Before it could be distributed, it would need emergency approval by the Food and Drug Administration.

Pfizer and Biontech are developing a vaccine candidate that uses genetic material from the virus, known as messenger RNA, to trigger the immune system without making the recipient sick.

The technology can create a vaccine quickly but has not yet produced one that has been approved and marketed. Large-scale safety and efficacy trials are to begin this month.

The agreement with Pfizer is the largest one yet for ‘‘Operation Warp Speed,’’ the government’s crash coronavirus vaccine program. The federal government announced earlier this month that it would pay the Marylandbased company Novavax $1.6 billion to expedite the development of a coronavirus vaccine.