As much of the United States braces for its Covid-19 peak in coming weeks, state and public health officials are looking ahead to prepare the country to incrementally phase out stay-at-home orders. While some experts have projected timelines for when it's safe to reopen parts of the country, former FDA Commissioner Scott Gottlieb' recently released a report that outlines explicit criteria states should meet before they flip the switch:

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Gottlieb's conditions emphasize the critical roles testing and surveillance play in slowing the spread of the virusthe first step to relaxing social restrictions.

Ultimately, we think a community's ability to monitor the spread of Covid-19 boils down to their ability to answer three key questions about their population: Who is immune? Who is contagious? Where is the virus still spreading?

The narrative around a community's readiness to reopen businesses largely hinges on measuring potential immunity through the availability and efficacy of antibody testing. These tests, also known as serological tests, measure the amount of antibodies (IgG and IgM) in a person's bloodeven those considered asymptomatic. Understanding the amount of antibodies in a population clarifies the full scope of community spread and reveals the virus' true transmission and fatality rates.

However, antibody testing is no a silver bullet. Stories of "reactivated" cases are reminders of how little is known about a patient's immunity after recovering from the virus. Dawn Bowdish, a professor of pathology and molecular medicine at McMaster University in Ontario told Scientific American, "We simply don't know yet what it takes to be effectively protected from this infection."

Where is it happening already?

After a small county in Colorado failed to launch a county-wide serology testing program, large-panel studies using serological tests by the National Institutes of Health and Beaumont Health Research Institute are center stage for mass Covid-19 immunity research. Findings from Beaumont's study will be particularly valuable as it is open to all 38,000 Beaumont Health employees, making it the largest study focused on the susceptibility of health care workers and their antibody responses to Covid-19. Should results prove fruitful, communities could use a variety of tactics to open up economic activity and jobs to immune individuals, such as immunity passports being considered in other countries.

What is in the way of doing more?

The short answer here is a lack of FDA-approved antibody tests. Compared to PCR tests, developing an accurate antibody test is particularly difficult because the threat of false positive is high. If the test lacks specificity, previous exposure to other viruses within the coronavirus family, like any of the four that cause the common cold, can lead to a false positive. So far, three antibody tests have EUA approval from the FDA: Cellex and Chembio's rapid tests and Ortho Clinical Diagnostics high-throughput test. At least 70 other antibody test makers have validated and are planning to market their tests in the United States under the FDA's "Policy D" for serology tests, though these tests are not FDA-approved.

While Cellex's 15-minute, rapid test has speed on its side, it is limited to processing one specimen at a time. This won't be sufficient for widespread testing until specimens can be processed on automated, high-throughput instruments.

Another underlying challenge that requires stay-at-home orders stay in effect is the lack of visibility into infectiousness. Health officials are vying for tools that will predict where outbreaks will recur and who will need care.

To complement testing, experts argue an augmented disease surveillance system is needed to give officials a national view of where patients seek care and for what symptoms. Tracking demand for Covid-19-related care can help leaders assess the infectiousness of their regions and make informed decisions about reopening while enabling public health officials to distribute resources based on near real-time data.

Where is it happening already?

The private sector is playing a big role here. Advisory Board's Andrew Rebhan spoke with Kinsa the public health company collecting up to 162,000 daily temperature readings from their internet-connected thermometers to create the U.S. Health Weather Map, which allows consumers to understand where and when an illness is spreading. Scripps and UCSF are researching whether biometric data from wearable fitness devices could predict where health care workers are about to fall ill regionally. Genomics company, DxTerity Diagnostics, launched a subscription Covid-19 testing service for employers to safely screen for, and intercept, their pre-symptomatic employees as they return to the office.

What is in the way of doing more?

Scaling and syncing disparate surveillance methods into one system will be a technical (and unlikely) feat. Feasibility aside, the prospect of sharing personal health information with any organization will always prompt a discussion about privacy. Privacy laws are likely to preclude the U.S. from considering South Korea's surveillance strategies, regardless of their efficacy. For now, public-private partnerships are the keystone to monitoring the infectiousness of the virus and proactively managing the response.

The CDC cites "very aggressive" contact tracing of those testing positive for Covid-19, and a major scale-up of personnel to take on that work, as key competencies the country must invest in to safely reopen. Former CDC Director Tom Frieden estimates upwards of 300,000 dedicated contact tracers are needed just to match the scale of contact tracing in Wuhan, China. National contact tracing efforts require laborious interviewing and investigative work from trained public health experts, but they won't be acting alone as the technology sector joins the fight.

Where is it happening already?

Massachusetts Gov. Charlie Baker (R) formed the nation's first Contact Tracing Collaboration with global non-profit, Partners In Health, to train and deploy 1,000 public health students across the state as contact tracers.

Tech giants, Apple and Google are teaming up to create a contact-tracing tool for their billions of iPhone and Android users. The ability to wirelessly exchange anonymous information via apps run by public health authorities is expected by mid-May. Covid-19 positive users can opt to upload their test results to a public health app, which will notify other users who came into close proximity over the previous several days and encourage them to isolate themselves.

What is in the way of doing more?

The U.S. has thousands of newly idled workers who could be activated for contact tracing. Nearly 7,000 PeaceCorps volunteers returned home in mid-March and there are thousands more "furloughed public employees, phone bank staff (most tracing work is done by phone), workers from health organizations, social service and nonprofit agencies, and recent graduates," Frieden wrote in a New York Times opinion piece. Expediting training for furloughed employees could reactivate part of the unemployed workforce and supplement technology-based contact tracing efforts. However, the cost and scope of such a national recruiting effort coming together in coming weeks appears unrealistic.

Advisory Board's Jackie Kimmell and Jordan Angers also note that Apple and Google's technology solution is not without limits. The bluetooth connection that contact tracing tech relies on is notoriously inconsistent and can lead to false positives. More challenging is that the technology's use is voluntary so it is only as effective as the number of people who decide to share their testing information.

Many officials are already pointing to the next phase of the new coronavirus epidemic, but without an understanding from local government about how the virus is spreading in their communitiesand how their communities are respondingthe country could be hamstrung on figuring out that "opening date" and therefore see continued micro-surges.

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We can't reopen the country without answering these 3 questions - The Daily Briefing