Many Americans are hopeful that the summer will mark the end of social distancing, but health experts are projecting that some form of social distancing will be in place for months—with one group of researchers predicting the United States will need to practice intermittent social distancing through 2022.

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What the US' path forward might look like

People across the country are questioning how long social distancing and stay-at-home orders will last. While there are many unknowns that make those predictions difficult—such as whether the virus' spread will change with the seasons and whether infected patients develop immunity and how long that immunity lasts—several public health experts and think tanks have released plans outlining situations in which the United States could safely lift social distancing measures.

Two of the most prominent plans being circulated today are: the American Enterprise Institute's (AEI) roadmap, whose authors include former FDA commissioner Scott Gottlieb, and the Center for American Progress' (CAP) plan, whose authors include prominent health policy expert and bioethicist Ezekiel Emanuel. Other models also have been released by Nobel Prize-winning economist Paul Romer and Harvard University's T.H. Chan School of Public Health.

While each of the plans differs in the details, Vox reports that they all broadly outline a three-phase recovery:

• Phase one, which Americans are currently in, requires widespread social distancing to flatten the curve to prevent the U.S. health care system from being overrun;
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• Phase two, which eases some social distancing measures to allow businesses to reopen, but continues to place restrictions on large public gatherings. This phase also would require some form of public health system surveillance to expand testing and monitor the viruses spread; and
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• Phase three, which would require the development of an effective vaccine to prevent the virus' spread or a drug to treat Covid-19.

Phase three would effectively end social distancing in the United States, but each plan lays out a different timeline for how to get there—and paints a different picture of what "normal" might look like when those measures are lifted.

How long will we need to practice social distancing? Experts weigh in.

Most of the plans call for an initial lockdown period of varying lengths.

For instance, CAP's plan states that widespread stay-at-home policies should not be lifted until transmission levels are down to 18 new cases per one million people per day, or the level "South Korea was able to suppress transmission without locking down society." The plan, which was published April 3, estimated the United States' transmission level at the time was 76 new cases per one million people per day. 

Put another way, CAP's plan estimates, at a minimum, the stay-at-home policy should remain in effect for at least 45 days, beginning April 5, to reach that threshold. If transmission levels remain high, the lockdown could be extended.

Meanwhile, AEP's plan proposes the country wait to ease social distancing measures until two weeks after there's been a sustained reduction in new cases. Gottlieb didn't have a firm estimate on when that would be, but in an interview, he told Vox, "My sense is that we haven't turned the corner."

Both plans also state that the country would have to prepare the health care system for mass treatment and case tracking before reopening, which would require having enough personal protective equipment (PPE) for all health care workers and some form of surveillance system that would track and identify community spread of the infection.

In addition, the plans state that the United States would have to develop the capacity to treat and test everyone who presents symptoms of Covid-19 before lifting stay-at-home orders. Just how many tests would be needed varies by plan, but both note that scaling testing in the country could be difficult, as many of the products required to manufacturer and conduct tests are in short supply—and largely fall outside of the United States' supply chain.

Gottlieb, whose plan calls for the capacity to test 2-3 million samples per week, said, "I don't think we're gonna get there by May." He added, "I think we have the ability to get there by September, but we need to be doing a lot of things right now to invest in that."

What life looks like after phase one

Once these milestones are reached, the plans say states can begin to think about rolling back social distancing measures. However, both plans say this must be done incrementally.

For instance, Gottlieb said, "You'll probably lift the stay-at-home orders, but you'll tell people to wear a mask if they go out for a period of time. You'll allow certain businesses to go back to work, but you'll tell businesses that they have to put certain restrictions in place to try to reduce the number of people who congregate together."

Gottlieb said he expects the last normal activity that will be introduced is public gatherings in places like bars, venues, concerts, and clubs. In fact, AEP's plan calls for continued bans on gatherings of more than 50 people until a vaccine or effective treatment is developed—an outcome the plans generally predict is 12-18 months away.

Some public health experts say it could be up to two years away. Michael Osterholm, an infectious-disease epidemiologist at the University of Minnesota, said, "I think people haven't understood that this isn't about the next couple of weeks. This is about the next two years."

In the interim, public health experts say the United States will need to responsive to flare-ups of Covid-19 that occur throughout the country. A recent study by researchers from Harvard's T.H. Chan School of Public Health projected that addressing those flare-ups could require intermittent social distancing measures through 2022, unless an effective treatment or vaccine is developed or hospital capacity increases. The researchers' computer models suggested lifting social distancing measures after 20 weeks would effectively delay the epidemic's peak, not control it.

The reality though, according to public health experts, is that it's impossible to determine an exact date for when life will return to normal—or what normal may look—without a vaccine.

 "I don't think there's going to be a binary point in time when we just return to what we were doing," Gottlieb said. "I think world history is permanently altered by this episode" (Tozzi, Bloomberg, 4/14; Branswell, STAT News, 4/14; Klein, Vox, 4/14; Gottlieb et al., AEI report, 3/29; Emanuel et al., Center for American Progress, 4/3; Yong, The Atlantic, 4/14; Lopez, Vox, 4/14).