But he said in a briefing Wednesday with reporters, “I think that we need to accept that we are in the early stages of a pandemic. ... I would like to emphasize the pandemic is only just getting started."

“I think that there are understandable anxieties, and obviously there are understandable different approaches to what people characterize as a lockdown,” said William Hanage, a professor at the Harvard T. H. Chan School of Public Health.

People may be getting weary of being cooped up at home and heartened by reports of a flattening curve. But it’s too soon to declare victory against the coronavirus pandemic, according to a Harvard epidemiology expert.


Hanage said some areas may seem to be moving past the peak of the surge, but said, “It’s important to note that that decline is not, we believe, as a result of immunity to the virus, but rather as a consequence of the actions that we humans have been taking in order to try and stop new transmission chains being initiated.”

“It’s quite possible that cases are dropping ... but I think it’s stretching credulity to suggest that means the pandemic is past,” Hanage said.

He said that in order for the pandemic to be over, somewhere between 60 and 75 percent of the world’s population would have to be infected, giving rise to herd immunity.

“We don’t have evidence to think that that is what’s happened during the initial surge,” he said.

Hanage also emphasized that any plan to reopen the economy should have increased testing as a requirement.

“A prerequisite for moving forward needs to be the ability to detect if we have a surge building that is going to threaten health care. That means testing,” he said. “If you get a new surge building and you don’t detect it, then you could be in a very bad situation very quickly.”


Hanage said if social distancing restrictions are dropped, the virus could make a comeback in the fall, or even as early as the summer.

“What we have to remember is that as we start changing things, the opportunity for future surges could be there,” he said. “They definitely could happen.”

Instead of dropping restrictions, he said, “We should be trying to figure out ways to refine what we’re doing now,” and trying to figure out the measures that are “most helpful and most sustainable" and have the largest effect.

“I really think it’s extremely important that we manage to balance the response to this with economic activity, but I think that one of the things we’ve got to remember is we’ve got to keep a very close eye on it," he said.

“One of my major concerns at the moment is I’m detecting a sense among folks that this is coming to an end, whereas, actually, we’re really just in the beginning,” he said.

President Trump, who is anxious to reopen the economy, at a briefing later Wednesday downplayed the idea that the virus could see a resurgence, saying if it did “it’s not going to be like it was. ... It’s also possible it doesn’t come back at all.”

But his top experts disagreed. “There will be coronavirus in the fall,” Dr. Anthony S. Fauci, the federal government’s top infectious disease expert, said as Trump looked on.


Fauci also said that "whether or not it’s going to be big or small is going to depend on our response.”

Material from Globe wire services was used in this report.

Martin finucane can be reached at martin.finucane@globe.com