Instead of requiring people to take frequent coronavirus tests, which have proven costly and slow in being processed, the Scripps Research professor’s system works by relying on anonymized data collected from thousands of volunteers who wear smartwatches and fitness trackers. During a trial that started in March, the system has been able to provide an early warning of small regional outbreaks by looking for a telltale symptom of infection that’s easy to spot in the health data collected by wearables: a rise in resting heart rates.

“There’s no way to get real surveillance with just testing,” Topol says. “We can’t do it frequently enough on a mass scale. But this you can do on that scale and you’re going to get a continuous signal.”

The entire wearables industry has mobilized to help combat the spread of COVID-19, as scientists have found that even simple data collected by the devices such as heart rates, amount of sleep, and number of steps per day can be used to help predict disease outbreaks. Then health authorities can home in on the hotspots early to limit the spread of the disease.

Fitbit, Apple, Garmin and others have donated devices to further some early studies and have helped spread the word by encouraging their customers to participate. Some research is also looking at whether apps could be designed to give warnings to individual users, suggesting that they should quarantine and get tested as soon as possible.

There’s still one major problem for Topol’s project, called the Digital Engagement & Tracking for Early Control & Treatment, or DETECT, study. With only about 40,000 participants, it’s too small to provide strong warning signals nationwide. “To do it well, we need pretty dense coverage,” Topol says, like hundreds of thousands to millions of participants.

Fitbit and pharmacy chains CVS and Walgreens have helped spread the word, but it hasn’t been nearly enough yet. Anyone who is interested can sign up at the web site that Scripps set up.

In Germany, the national health research agency, the Robert Koch Institute, backed a similar effort and quickly signed up more than half a million volunteers. Combined with other measures, like contact tracing teams, the wearables data helped Germany get the epidemic under control. The country is seeing only about 500 new cases daily, down from a peak of almost 7,000 daily in March.  

“We don’t have anything like that coordinated national effort here,” Topol says. “We don’t have national support.”

At Fitbit, the hope is also to develop a warning for individual users in addition to contributing to regional warning systems like DETECT. Researchers are looking for a confluence of symptoms indicating an early sign of infection.

“How can we help say that someone should go get testing and when they should go get testing,” Fitbit co-founder and chief technology officer Eric Friedman asks. “We thought some of the disease detection work that we were already working on could be useful.”

So the company added a COVID-19 tracking study right in its own app. So far 100,000 people have agreed to participate including 900 who have tested positive for the disease. That has allowed researchers to review the Fitbit data from before the positive tests to look for warning signs and the early analysis is promising.

“We are hoping to have something available to people at some point,” Friedman says without getting more specific. The company isn’t ready to announce any kind of COVID-19 warning feature yet, he says.

Apple, the maker of the Apple Watch, declined to comment.

Garmin said it is participating in many studies related to COVID-19 detection but doesn’t have a feature to alert individual users. Still, Garmin users could monitor trends in their own health data to look for warning signs, says Scott Burgett, director of Garmin health engineering.

“The more you know about your body and what your ‘baseline’ is, the more you’re able to tell if something is off,” he says. “Because Garmin lets you see your health stats over time, it is easy to track trends and notice deviations.”

A study at the University of California San Francisco is monitoring volunteers who wear an Oura Ring, a $300 smart ring worn on a finger that collects data including pulse rate, temperature, and movement. UCSF Prof. Ashley Mason, who is working on the study, said it was too soon to draw any conclusions, however. “We can’t comment on implications in the absence of rigorously collected and reviewed data,” she says.

One potential problem with the wearables-based COVID-19 warning systems, which has plagued other tech-related health initiatives, is the uneven distribution of the devices. If people in low-income neighborhoods are less likely to own smartwatches or sign up to participate in the warning projects, for example, they won’t get the benefit of the early warnings.

For Duke University’s COVID-19 wearables study, called CovIdentify, the researchers are trying to address the problem of unequal access by seeking donations from companies like Apple and Garmin and distributing free devices.

“We are absolutely concerned,” says Dr. Jessilyn Dunn, who is leading the university’s efforts. “We are seeking additional funding and/or partnerships with wearables companies to better include underserved communities so that the technology is developed equitably.”