One of the keys to reopening the economy is having enough tests to diagnose coronavirus infections, with the goal being to quickly identify new cases, isolate them, and track down others who may have been exposed.

“We’ve done such a good job of social distancing that we expect the rate of immunity to be quite low, which means we would expect there to be, over the course of the next several months, periodic outbreaks of the disease,” said Dr. Christopher Woods, a professor of medicine and infectious diseases at Duke University. “But now we hope to have the diagnostic tools and the public health tools to contain those outbreaks as they occur.”

Coronavirus testing in the United States has been slow from the start and we’re still only testing roughly a million people a week. Though President Donald Trump said Thursday that we’re doing a “great job” on testing, public health experts have said the number of people tested should be far higher before social distancing eases up — anywhere from 3 million to 30 million a week, to 20 million or more a day.

Full coverage of the coronavirus outbreak

Problems persist, including shortages of testing supplies and equipment, and overburdened laboratories that can’t keep up with unprecedented demand.

“The sheer volume of testing that a lab is doing is so much higher than it would typically be,” said Dr. Angela Caliendo, a professor of medicine at Brown University and a member of the board of directors of the Infectious Diseases Society of America.

“We’re clearly making progress from where we were a month ago in regard to the availability of supplies,” Caliendo told NBC News. But it takes time for manufacturers to scale up.

How do we get to universally available tests across the country?

No one knows when there will be enough supplies.

“That’s really the $64-million-dollar question, or in this case the $25-billion-dollar question,” Scott Becker, CEO of the Association of Public Health Laboratories, said.

Fixing holes in the supply chain is obviously critical to expanded testing and each week is bringing “minor improvements,” Becker said.

But the problem is massive.

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“These shortages are global shortages,” he said. “It’s a global supply chain.”

As manufacturers work to scale up production, experts say there are some other ways to help achieve more widespread testing:

Emergency network for testing

This week, the Rockefeller Foundation released a “National COVID-19 Testing Action Plan” that details a testing optimization initiative to allow better coordination about lab needs.

“There are different bottlenecks with reagents, swabs, whatever,” said Dr. Jonathan Quick, the foundation’s managing director for pandemic response, preparedness and prevention. “But the idea is we need to be in real-time identifying those bottlenecks and then figuring out what action to take.”

A national system could help labs more easily track down supplies, according to Quick. “A part of this program is an emergency network for COVID testing that links together states and regions so they know where supplies can be purchased, and they have, in essence, kind of buyers clubs,” he said.

In another plan also supported by the Rockefeller Foundation, experts at Harvard University’s Edmond J. Safra Center for Ethics released a “Roadmap to Pandemic Resilience,” which calls for a pandemic testing board set up by the federal government that secures the testing supplies and the necessary infrastructure.

California has managed to get enough of a handle on testing, through its coronavirus testing task force, to become the first state to expand testing to asymptomatic people in high-risk settings such as nursing homes and prisons, according to officials.

“It’s taken a tremendous amount of effort,” said Dr. Bob Kocher, a member of the task force and an adjunct professor of medicine at Stanford University.

But Kocher said states' communication with the federal government also is key. California Gov. Gavin Newsom, for instance, spoke with Trump to secure several hundred thousand more swabs in the coming weeks.

Other types of COVID-19 tests

The Harvard report also urges innovations to broaden testing. Experts say that if there were a greater variety of good testing tools widely available, there still would be some options when various pieces in the supply chain are missing.

Most coronavirus detection is done with polymerase chain reaction (PCR) testing, which requires high-tech lab equipment. Testing sites purchase company kits and all the supplies needed to run the tests, including swabs to gather samples from a patient’s nose or throat, reagent solutions, and personal protective equipment such as masks and gloves.

Other types of tests also are now being offered with limited availability that promise to increase testing access further, though there are questions about whether they are as reliable as PCR testing. Some tests give rapid results at the point of care, avoiding the need to send samples to a lab. A saliva test offers an easier way to collect samples. Earlier this week, the Food and Drug Administration approved an at-home test, in which patients send a nasal swab sample to a lab, but this test is first being offered to health care professionals and other frontline workers.

More domestic production

The pandemic has seen drive-through testing sites pop up around the nation. It’s not always possible or safe to come into a clinic for testing. And some areas, particularly rural regions, may not have enough testing sites.

Experts say it’s important to expand testing sites to underserved areas and go out to high-risk communities like nursing-home residents and homeless people with testing. Achieving these goals requires not only the right supplies but also enough staff to perform the tests and contact tracing.

Kocher, of the California task force, believes it would help if the federal government made greater use of the Defense Production Act to boost supply manufacturing. Trump has said he invoked the DPA to ramp up production of swabs.

“As California, I’m competing with other states to buy things,” Kocher said. “But some of this comes down to, did I buy this first? That’s not a great system. And so, we need more domestic production of these supplies. The whole world is trying to buy them.”

When will sufficient testing be in place?

Earlier this week, former FDA Commissioner Dr. Scott Gottlieb told "TODAY" that he’d like to see the United States testing about 1 percent of the population — about 3 million people — on a weekly basis. But he fears that level of testing and contact tracing may not be possible as the economy starts to reopen.

“Hopefully, we’ll be there by September,” he said. “So the reality is, from a clinical standpoint, we’re probably not going to have the optimal amount of testing, but we’ll have better testing in place than we did.”

Quick, of the Rockefeller Foundation, is more optimistic. While the foundation is hoping for 30 million tests a week to be performed over the next six months, the immediate goal is to reach 3 million tests a week within a couple of months.

“I think we’ll get there before September,” he said. “But we’ve got to speed it up.”