President Trump has been promising the imminent arrival of a vaccine to halt the spread of the coronavirus, the novel germ that has sickened more than 100,000 people worldwide, killed more than 3,400 and is now spreading in the United States.
Federal health officials have repeatedly pointed out that his timetable is off — that it will take at least a year — but his single-minded focus on warp-speed production of a new vaccine represents a striking philosophical shift. For years, Mr. Trump was an extreme vaccine skeptic who not only blamed childhood immunizations for autism — a position that scientists have forcefully repudiated — but once boasted he had never had a flu shot.