Israel’s heavily digitized, community-based health system — all citizens, by law, must register with one of the country’s four H.M.O.s — and its centralized government have proved adept at orchestrating a national inoculation campaign, according to Israeli health experts.

With a population of nine million, Israel’s relatively small size has played a role as well, said Professor Balicer, who is also the chief innovation officer for Clalit, the largest of the country’s four H.M.O.s.

An aggressive procurement effort helped set the stage.

The health minister, Yuli Edelstein, said in an interview on Friday that Israel had entered into negotiations with drugmakers as an “early bird,” and that the companies were interested in supplying Israel because of its H.M.O.s’ reputation for efficiency and gathering reliable data.