But experts inside and outside the government still say they fear the White House will push the Food and Drug Administration to overlook insufficient data and give at least limited emergency approval to a vaccine, perhaps for use by specific groups like front-line health care workers, before the vote on Nov. 3.

“There are a lot of people on the inside of this process who are very nervous about whether the administration is going to reach their hand into the Warp Speed bucket, pull out one or two or three vaccines, and say, ‘We’ve tested it on a few thousand people, it looks safe, and now we are going to roll it out,’” said Dr. Paul A. Offit of the University of Pennsylvania, who is a member of the Food and Drug Administration’s vaccine advisory committee.

“They are really worried about that,” he added. “And they should be.”…

While White House officials do not specifically mention the election during the board’s discussions, people familiar with the conversations say they ask regularly about October, a date that hangs over the effort. Trump campaign advisers privately call a pre-election vaccine “the holy grail.”