There is both promise and peril in being a pioneer, and the people of Hokkaido have learned both lessons well over the past few months. After infections of COVID-19 on the Japanese island exploded following its annual winter festival this year, officials in February declared a state of emergency to control the disease. Soon after, new daily cases plummeted, and Hokkaido’s quick action was heralded as a beacon for the rest of Japan to follow.

But it wasn’t just infections that dropped; over the next month, agriculture and tourism business also dried up, and Hokkaido’s governor decided to ease social restrictions. However, compliance with limits on social interaction after weeks of sequestering was harder this time around. Within a month, Hokkaido’s new COVID-19 infections jumped by 80%, and the governor had to reinstate lockdown policies.

There are similar stories from Singapore, Hong Kong and Germany, and all serve as sobering lessons for the decision-makers in the U.S. who are under increasing pressure to reopen the country to reactivate its stalled economy. The tension is built into the pandemic: while public-health metrics all point toward extended social isolation and a more gradual reopening of society, the decisions are made by politicians. Already, some state governors are allowing businesses such as nail salons, barbershops and gyms to reopen to prevent bankruptcies and economic ruin.

Illustration by Ben Wiseman for Time

How to proceed? The U.S. urgently needs to restart, but no economy can function if an infectious disease like COVID-19 continues to sicken the workforce and keep customers to a trickle. More than a million Americans have had the disease, but it is not yet known whether recovering can provide lasting, or any, immunity. Which means much of the country’s nearly 330 million people remain at risk for infection with SARS-CoV-2, the virus that causes the illness, in a too-sudden return to normal. “Even in the hardest-hit places [in the U.S.], fewer than 1 in 10 people have been infected. So not only could COVID-19 come roaring back, but it could get five times or close to 10 times worse than it is now,” says Dr. Tom Frieden, president and CEO of Resolve to Save Lives and former director of the U.S. Centers for Disease Control and Prevention (CDC). “The only way forward is to suppress cases and clusters of cases rapidly.”

Under President Trump’s guidelines for Opening Up America Again, states would move through three phases of gradually loosening social restrictions. The threshold for entering each stage toward normality is declines in the number of new COVID-19 cases in the previous 14 days. Gyms, movie theaters and sports stadiums would be the first to reopen, although people would have to remain 6 ft. from one another and avoid intimate gatherings of more than 10. Next, schools and bars could reopen with limitations, and finally, if cases continued to decline, most people could return to work. Health experts warn, however, that the return to normality can’t be only a straight progression–if cases start to inch upward, then social distancing and shelter-in-place directives will have to be renewed.

The only way to calibrate those decisions is to know where the new infections are. When it comes to conquering an infectious disease, the adage “know your enemy” is remarkably apt. Or, even more important, know where your enemy is. Tracking an invisible virus is the key to controlling it, and the quickest and most reliable strategy for that is to build a robust system to test anyone who might be infected. For the U.S. to reopen its economy, “We’re going to have to find those people who are infected, and not just wait for them to come to us,” says Barry Bloom, a professor at the Harvard T.H. Chan School of Public Health. “The bottom line is, it’s testing, testing, testing–so we know where the epidemic is before we can relax any stringencies in a stepwise fashion.”

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases and a member of the White House Coronavirus Task Force, tells TIME, “We must have in place the capability that when we do start to see cases come back–and I’ll guarantee you that they will–to identify by testing, [and then] isolate and contact-trace to get people out of circulation who are infected.”

It may take tens of millions of tests per week to do that, and the problem is the U.S.’s testing capacity may not be ready yet. “There is absolutely no way on earth, on this planet or any other planet, that we can do 20 million tests a day, or even 5 million tests a day,” says Admiral Brett Giroir, the assistant secretary for health who is overseeing the government’s testing response.

1. TESTING

Widespread testing can yank away the curtain that hides SARS-CoV-2, revealing where there are clusters of people who are infected by the virus but not showing symptoms, and thus aren’t aware they might be spreading it to others. That, in turn, will lead to more targeted efforts to isolate anyone who is infectious. And, if all the people who came in contact with an infected person were also tested, it would help local health authorities trace how the virus is moving through a community. It’s basic, boots-on-the-ground disease control.

The U.S., however, stumbled on testing in the early days of the pandemic, and those failures led to a dramatic surge in cases that climbed more quickly than in other countries. Thanks to a combination of contamination issues that delayed the original test from the CDC, and regulatory requirements that prevented commercial and academic labs from immediately developing their own assays, “It’s still the case that testing isn’t nearly as readily available as it needs to be,” says Frieden. As of this writing, just over 1 million tests for COVID-19 are performed in the U.S. each week, which is woefully inadequate, Fauci says.

Public-health experts estimate that the current U.S. testing rate has to triple simply to include all the people who are considered highest priority for testing, including health care workers and nursing-home residents. To fold in all of those who should be tested if gyms and restaurants reopen, the number of daily tests has to increase by tens of millions. Ideally, anyone with symptoms like a cough, fever or shortness of breath should be tested, as should anyone who is sick and living in a group facility like a dormitory, along with any patient admitted to a hospital for any reason. Family members and others with close contact to someone who tests positive should also be tested.

Boosting testing volume is about not just manufacturing more tests but also ensuring that they’re relatively easy to take. So at-home testing kits that are just becoming available–which still require a doctor’s prescription but won’t require people to go to a doctor’s office or health facility to provide a sample–will become more critical as states gradually reopen. Several companies are also offering COVID-19 tests, approved by the U.S. Food and Drug Administration (FDA), that don’t require doctors or patients to sample from deep in the back of the nose and throat, but instead swab the inside of the nostrils or provide a small amount of saliva, making it easier even for non–health professionals to provide samples.

While testing capacity in the U.S. is gaining ground, the road ahead remains long. The health system has never had to manage testing at the scale needed to control this pandemic, and doing so may require equally unprecedented solutions. Anticipating that the gap between testing need and testing capacity will only yawn wider as states reopen, the Rockefeller Foundation, for example, has proposed a coordinated regional command system for testing that would track and redirect supplies to where they are needed. The foundation’s action plan, backed by a $15 million initial investment, also calls for engaging hundreds, even thousands, of smaller labs that currently don’t perform tests for the public. So far, leaders from California and five U.S. cities are working to implement the plan and increase access to testing. (The foundation sponsored a recent TIME 100 Talk.)

2. TRACKING

Once testing at scale is in place, local trends should dictate when and how a particular region might begin to emerge from self-isolation. Loosening of social-distancing policies won’t happen universally across the nation, since the burden of disease is vastly different from New York to Nevada. Each region–whether defined as a community, a state or a group of states–will have to make customized decisions about releasing its residents in phases based on its specific disease trajectory as well as its population density, among other factors.

There are, however, some universal benchmarks. Bloom and others believe new daily cases, identified by wide-scale testing, would have to fall consistently in a given region for at least two weeks before leaders can start discussing reopening businesses and schools. At that point, health experts would investigate where the new cases are. If they’re confined to local and sporadic clusters, that’s a sign that the virus’s circle of transmission is limited and potentially shrinking.

Such scenarios would mean not that the virus is necessarily going away, but that the local health system is in a decent position to manage the load of people who get infected. “We are not just staying home in the magical belief that the virus is going to go away,” says Frieden. “We are staying home so we can strengthen the health care and public-health systems.” The idea isn’t to eradicate coronavirus completely–at least not yet–but to bring its spread to manageable levels. As flare-ups occur, they can be doused with another critical contagion-fighting public-health technique: contact tracing. It doesn’t help to know who is infected if you’re not also investigating who else that person might have infected. In a study conducted in Shenzhen, China, researchers found that tracing contacts of people who tested positive helped reduce the time it took to isolate those who were infectious by nearly half.

Few riders are seen on the U-Bahn in Berlin in March 2020 Anja Lehmann—VISUM/Redux

This is the foundation of infectious-disease containment, but that doesn’t mean it’s easy. Google and Apple are collaborating on a digital solution to contact-trace at scale using smartphone and search data, but concerns about privacy remain. In New York, Governor Andrew Cuomo has formed a partnership with Bloomberg Philanthropies, the Johns Hopkins Bloomberg School of Public Health and the nonprofit Vital Strategies to build a first-of-its-kind training program to teach and certify contact tracers. The program will rely on call centers, digital technology and historical best practices to identify the contacts of people who are infected, track their whereabouts and the contacts of those contacts–and then educate those who need to self-isolate about how best to do that to protect the public’s health.

3. IMMUNIZING

Testing, isolation and contact tracing, however, are all essentially a backup plan for fighting an infectious virus like SARS-CoV-2. The only way to ensure that the virus won’t burn through a global population again is to build a better defense. And the most impenetrable fortress against a virus is immunity, gained–at the individual level–either by becoming infected and recovering or by getting vaccinated. “It doesn’t matter how much virus is out there, if people aren’t susceptible to getting it, then the virus will go away,” says Lisa Lee, associate vice president for research and innovation at Virginia Tech. Smallpox, for example, was eradicated thanks to immunization.

The goal is herd immunity: when nearly every person around the world develops these protections, the “herd” is able to protect the few, such as newborns, who aren’t protected or cannot be vaccinated. At this point, it is unclear if the human body naturally develops any after recovering from COVID-19. So as researchers work to figure that out, they are also racing to develop a vaccine. But although there are a variety of vaccine candidates in development and testing, it will likely take at least 12 months before the first people can be inoculated against SARS-CoV-2.

Without widespread immunity, public-health officials can only keep a close watch on new cases as they pop up, and suppress them so they don’t morph into widespread outbreaks. Which means that until the population at large is protected, some amount of social distancing will become a routine part of our lives. Even if a region shows all the right numbers–declining curves of new COVID-19 cases, fewer deaths and more hospital discharges than admissions–that doesn’t mean restaurants, sports arenas, shopping centers and workplaces should go back to the status quo. “Locking down isn’t just to lock down,” says Fauci. “It’s to give you time so that when you open up again, you can come out swinging … when the virus rears its head, you have the capability to identify, isolate and contact-trace and snuff it down before [cases turn into] outbreaks.”

4. THE NEW NORMAL

Especially in hard-hit, densely populated areas like New York City, at minimum, everyone might need to wear face masks in public to prevent the spread of virus-containing respiratory particles; public-transit riders may not be sitting shoulder to shoulder; diners at restaurants might need to be seated 6 ft. apart; and we might significantly cut back on physical contact. “This may turn out to be the death of the handshake,” says Dr. Hilary Babcock, an infectious-disease specialist at Washington University School of Medicine.

Accepting these changes to daily life is accepting the reality that emerging from this pandemic won’t be like flipping a switch. “This is a public-health emergency, and only public health is going to get us out of this,” says Frieden. “The economy, and society, depend on public health getting this right.” And that means not just testing and identifying people who are infected, along with their contacts, but rethinking how self-isolation fits into broader policy decisions. The massive quarantine of these past few months was unprecedented, but more limited isolation, on a case-by-case or family-by-family basis, may become the norm for at least a while. And public-health officials may have to work with local community leaders to accommodate more formal, structured ways to self-isolate in order to effectively balance the public good of such measures with the rights and dignity of individuals. For example, Frieden says, “we should be offering voluntary isolation for every person infected,” in the form of designated hotels or living quarters to support people who cannot stay in their current homes without putting others at risk.

These, of course, won’t be the only new ubiquities in a post-COVID-19 world. Microbial threats like coronaviruses will inevitably move from the bottom to the top of public-health priority lists, and the dangers of infectious diseases will loom larger in our collective conscious. They will have to, if we have any hope of avoiding further drastic lockdowns and forever changing the way we interact with each other.

–With reporting by W.J. HENNIGAN/WASHINGTON and ABIGAIL LEONARD/TOKYO

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