Trump hoping for a vaccine by Election Day -- but doctors say that's impossible

Don't expect a coronavirus vaccine by Election Day, no matter what President Donald Trump promises.

Moderna was the first company to begin Phase 3 clinical trials in the U.S. and hopes to enroll 30,000 subjects by September, but so far has signed up only 4,536 and opened up just 54 of 89 study sites, reported CNN.

The company won't hit its goal for next month if that pace continues, but infectious disease experts say Moderna still won't have a vaccine ready for the market in time for the Nov. 3 election.

"I don't see how that would be possible," said Dr. Paul Offit, a vaccinologist at Children's Hospital of Philadelphia.

"There's no way," agreed Dr. Peter Hotez, a vaccinologist at Baylor College of Medicine. "There's just no way."

Once the company enrolls subjects and injects them with their first shot, they must then wait 28 days for a second shot, which means participants who enroll at the end of September wouldn't get their second shots until the end of October -- and then wait another two weeks for the vaccine to become fully effective.

"That takes you past Election Day," Offit said.

Researchers must then wait and see whether any participants get sick with COVID-19.

Both Offit and Hotez predicted results from Moderna's study wouldn't be available until the first quarter of 2021, at the earliest, and they also splashed cold water on a timetable from Pfizer, which began Phase 2/3 of its own study on July 27.

Pfizer hopes to know by the end of September or early October whether its vaccine worked, after dosing more than 2,000 by the end of last week, but Offit and Hotez pointed out that study must also wait for its second dose to determine whether it was effective.

"Maybe by Inauguration Day we might have a glimmer of whether the vaccine is working and be able to assess its safety," Hotez said.