Smartphone-based COVID-19 tracking apps are likely to play a role in a new national plan by President-elect Joe Biden to contain the coronavirus as daily case counts, hospitalizations and deaths from the disease skyrocket across the country.
Fewer than half the 50 states have launched a smartphone-based exposure notification app, and a few states have them in development.
The sparse availability of COVID-19 tracking apps may change with a push from Biden’s task force, said Scott Becker, CEO of the Association of Public Health Laboratories, an industry group that works with federal agencies on public health issues.
“I’m hopeful that more and more states are going to build and launch exposure notification apps,” Becker said.
Biden’s 13-member coronavirus task force plans to expand nationwide testing capabilities, create a cadre of health care workers to conduct contact tracing, ramp up production of personal protective equipment and implement a vaccine distribution plan.
Two weeks after the U.S. presidential election, new COVID-19 cases, daily death counts and hospitalizations all have reached record highs. Hospitals in many states are reaching peak capacity and are reporting shortages of gloves, masks and other protective gear.
After getting off to a slow start and further delayed by privacy concerns, some states have built contact-tracing apps based on the framework created earlier this year by Apple and Google. Other states, lacking the resources to design their own app, have begun to use a simplified version of the Apple-Google framework known as EN Express — “EN” stands for exposure notification — and comes bundled with smartphone operating systems.
Both approaches use Bluetooth signals to send and receive codes that allow users with apps to figure out if they crossed paths with an infected individual. The codes, known as “keys,” carry no personal identifying information of a user and are stored on a server for 14 days.
An app user who tests positive for COVID-19 has the option of sharing that information through the app. Apps check with the server on a regular basis to see which app user has tested positive for COVID-19 and which keys belonging to other users were in the vicinity of the infected individual. Using that information, apps send a warning to a user who may have been exposed to an infected person.
Preventing spread through tracing
Electronic tracking and contact tracing are critical to containing the spread of the pandemic and helps public health authorities find everyone who may have been exposed to an infected individual and stop them from spreading it to others.
But in the absence of a national strategy under the Trump administration, some large states, including Florida and Texas, haven’t yet developed an app.
Some states with apps also have limited their reach by choosing to store users’ keys generated by the apps only within the state, which means Americans traveling across state lines may not be able to tell if they were exposed to an infected person.
To address that bottleneck, the Association of Public Health Laboratories hosts a national key server that can store codes from app users in all the states. Ten states already use the national server, and another five states are in the process of moving their data to the national server.
If all states store their keys on the national server, it would create a de facto national database and help with reopening large parts of the economy, Becker said.
“This is another tool that can help get the country opening in the sense of allowing interstate travel with notifications,” Becker said.
A user with a Virginia state app traveling to California, for example, can get notified if he or she was exposed to an infected person in the Golden State and vice versa, Becker said.
To have a nationwide network of apps that can connect and share data, more states need to step up and start offering a tracking app, Becker said.
The Biden administration’s effort to kick-start a coordinated national effort means that “we would have strong messages from the federal level down to the state level about all aspects of responding to the pandemic, and that includes exposure notification,” Becker said.
Adoption of tracing apps is inconsistent
Contact-tracing apps are only effective if enough people download and use them.
App usage varies by state and roughly seems to match the state’s political persuasion, with greater participation in Democrat-led states and lower in Republican-leaning ones.
In Virginia, a state where Democrats hold the governor’s office as well as both chambers of the legislature, as of Nov. 2, 743,000 state residents had downloaded the state’s COVIDWISE app, which was launched in August, said Jeff Stover, executive adviser to the commissioner of Virginia’s Department of Health.
That number represents about 17.5 percent of the target population of people between 18 and 65 years of age and who own a smartphone, Stover said, adding that downloads continue to grow.
Across the country in North Dakota, the rate of download is just 3 percent among the target population, said Tim Brookins, a Microsoft engineer who has developed the app for the Peace Garden State.
“Anecdotally, what we believe is happening is people with extra exposure — like essential workers, nursing home employees, medical workers and students — tend to download the app,” Brookins said. “While the overall percentage is somewhat disappointing, it may be higher within the high-risk population.”
But the lower downloads in the state may also be reflective of the state’s wide-open spaces and farming culture, where “people are so tired of restrictions and have reached the point of saying, ‘To hell with it,’” Brookins said.
Assessing the effectiveness of COVID-19 tracking apps by looking at downloads may be misleading, said Joanna Masel, professor of evolutionary biology and ecology at the University of Arizona, and a consultant to the state’s COVIDWATCH app.
Unlike other states that launched their apps with promotions for statewide use, the University of Arizona, which has developed and pilot-tested the app, has rolled it out in “defined communities,” Masel said.
The goal is to get higher adoption rates in universities, then expand it to Native American reservations in the state, large employers and then the broader community, Masel said. “That creates a network effect” and avoids potential technical failures that may come with everyone downloading the app at once, she said.
Unlike the basic functionality provided by the EN Express app, in Arizona, Masel and her researchers have tweaked the app to collect information on when COVID-19 patients start exhibiting symptoms, and also to send daily prompts to users reminding them to isolate.
The absence of a coordinated federal response at the start of the pandemic has led to different approaches in multiple states, and to the tech companies, Apple and Google, becoming the de facto regulators on what kind of data is collected by the apps, Masel said.
Biden’s coronavirus task force should set standards for what the Apple-Google framework should look like and what information should be collected, Masel said.