As President Vladimir V. Putin of Russia triumphantly declared on Tuesday that his country had produced the world’s first coronavirus vaccine, public health experts in the United States worried that Mr. Trump would feel compelled to compete in a pharmaceutical manhood contest by hastily rolling out his own vaccine even before it is fully tested.

“I am sure that this will give him more impetus to push U.S. R&D and F.D.A. to move more quickly,” Dr. Margaret Hamburg, a Food and Drug Administration commissioner under President Barack Obama, said, referring to research and development. “If he believes that testing causes cases, I suspect he may believe that if you don’t test a vaccine or drug, they must be O.K.”…

“Judging from Trump’s history of seeming deference to Putin as well as an ongoing personal desire for a ‘win,’ Trump may wish to replicate at home what he sees as a Russian vaccine triumph,” said Monica Schoch-Spana, a senior scholar at the Johns Hopkins Center for Health Security.