“I think when people tell the public that there’s going to be a vaccine by the end of 2020, for example, I think they do a grave disservice to the public,” said Ken Frazier, the chief executive of pharmaceutical giant Merck, in a recent interview with Harvard Business School. “We don’t have a great history of introducing vaccines quickly in the middle of a pandemic. We want to keep that in mind.”

Spreading false hope and failing to come through is just one of the things that could further damage the public’s trust.

“You can’t give an optimistic message that the vaccine is going to be developed in December and then come December you don’t have a vaccine. Then people are wondering what happened,” said Vijay Samant, a vaccine expert who oversaw the production of three successful vaccines when he worked at Merck. “In the meantime, you know, they have given up social distancing in the assumption that the vaccine going to be developed in six months, and people are taken aback what’s going on, they lose confidence.”

Once a vaccine is available, it could still take six months to a year to vaccinate enough of the population to slow the spread.
“That’s if you’re lucky,” Samant said.