The companies said that protection plus a good safety record means the vaccine should qualify for emergency use authorization, something the Food and Drug Administration can grant before the final testing is fully complete. In addition to Friday’s FDA submission, they have already started “rolling” applications in Europe and the U.K. and intend to submit similar information soon…

Friday’s filing sets off a chain of events as the FDA and its independent advisers debate if the shots are ready. If so, still another government group will have to decide how the initial limited supplies are rationed out to anxiously awaiting Americans.

How much vaccine is available and when is a moving target, but initial supplies will be scarce and rationed. About 25 million doses of the Pfizer vaccine may become available in December, 30 million in January and 35 million more in February and March, according to information presented to the National Academy of Medicine this week. Recipients will need two doses, three weeks apart.