The U.S. government has agreed to buy 100 million doses of Moderna's experimental coronavirus vaccine for $1.5 billion, or $15 per dose.

Why it matters: The Trump administration, through Operation Warp Speed, has now bought initial batches of vaccines from Moderna, GlaxoSmithKline and Sanofi, Pfizer, Novavax, Johnson & Johnson and AstraZeneca before knowing whether they are safe and effective. The federal government also appears to own some of the patent rights associated with Moderna's vaccine.