Big unknowns about virus complicate getting back to normal

WASHINGTON (AP) — Reopening the U.S. economy is complicated by some troubling scientific questions about the new coronavirus that go beyond the logistics of whether enough tests are available.

In an ideal world, we’d get vaccinated and then get back to normal. But, despite unprecedented efforts, no vaccine will be ready any time soon.

“We're all going to be wearing masks for a while,” Dr. Rochelle Walensky, infectious diseases chief at Massachusetts General Hospital, predicted during a podcast with the Journal of the American Medical Association.

Three big unknowns top the worry list:

WHO’S CONTAGIOUS?

“The really unknown in this, to be completely transparent,” is asymptomatic spread, said Dr. Deborah Birx, the White House coronavirus task force coordinator.

From the beginning, authorities have rightly told people to stay home if they’re sick. But according to Dr. Anthony Fauci of the National Institutes of Health, somewhere between 25% and half of infected people might not show symptoms.

That means there’s no way to tell if you’re standing next to someone who’s contagious in the checkout line.

And even in people who eventually develop symptoms, it’s not clear exactly how soon after infection they can spread the virus. That’s one reason U.S. officials recently encouraged people to wear cloth masks in public, even as they try to keep 6 feet away from others.

To reopen the economy, officials are emphasizing the availability of more virus tests. That’s key to spotting and isolating the infected, and tracing and quarantining the people they may have exposed. But it's not a panacea.

“If you get a test today, that does not mean that tomorrow or the next day or the next day or the next day as you get exposed, perhaps from someone who may not...