Covid-19 tracing apps may see renewed push under Joe Biden


US President-elect Joe Biden is preparing for a long-overdue national effort to curb the spread of the coronavirus. That may include facilitating and promoting widespread use of smartphone-based tracing apps that have been developed and distributed in a state-by-state patchwork.

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Hot spot North Dakota: Acceptance of Covid safety measures is low in conservative states

US President-elect Joe Biden has promised a new national effort to combat the Covid-19 pandemic when he takes office in January. With daily case counts, hospitalizations, and deaths currently skyrocketing across the country, one part of that effort may rest on promoting widespread use of smartphone-based tracing apps that until now have been developed and distributed in a state-by-state patchwork.

Biden has announced a 13-member coronavirus task force, officially the "Transition Covid-19 Advisory Board," that includes health experts, doctors, and biomedical researchers. His plans include expanding nationwide testing capabilities, creating a cadre of health workers to conduct contact tracing, as well as ramping up production of personal protective equipment and implementing a vaccine distribution plan.  

The coronavirus conditions he will face are becoming more acute. Two weeks after the US presidential election, new Covid-19 cases in the country increased more than 30 percent to 11 million, and reports of daily deaths from the disease rose 10 percent, to a total of more than 245,000 fatalities since February. Hospitals in many states are reaching peak capacity, and healthcare workers once again are reporting shortages of protective gear.

Contact tracing got off to a slow start

Contact-tracing apps, aimed at arresting the viral spread by tracing people who test positive and notifying others who’ve been in their proximity, got off to a slow start earlier this year. Privacy concerns and other technical hurdles delayed development, until Apple and Google agreed to collaborate on a system based on Bluetooth signals that don’t identify the user in any way or give away a user’s location. Some states have begun to use a simplified version of the Apple-Google framework known as EN Express, which 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 tracing apps to figure out if they crossed paths with an infected individual. For the apps to work accurately, users have to keep their Bluetooth signals turned on all the time. The codes, known as keys, carry no personal identifying information and are stored on a server for only 14 days.

A user who tests positive for Covid-19 has the option of sharing that information through the app. State health departments then check the keys generated by users’ phones against those of infected patients and alert users who may have crossed paths with an infected individual.

Electronic tracing is critical to containing the spread of the virus and helps public health authorities find everyone who may have been exposed to a patient and stop them from transmitting it to others. But in the absence of a national strategy under the Trump administration, fewer than half the states have developed and promoted an app, while the rest – including large states like Florida and Texas – don’t yet have one.

Many of the states that offer an app have limited the reach of the systems by choosing to store users’ keys generated by the apps within the state. That means Americans traveling across state lines would not be able to use their app to know if they were exposed to an infected person. Countries of the European Union had the same issues until the European Commission developed a system to facilitate connectivity among member countries’ various apps.

Connecting across states

To address that bottleneck in the United States, the Association of Public Health Laboratories (APHL) 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 offering Covid-19 tracking apps store their keys on the national server, it would create a de facto national database, said Scott Becker, CEO of APHL.

“This is another tool that can help get the country opening, in the sense of allowing interstate travel with notifications,” Becker said. Americans traveling across state lines could do so without having to worry about being unknowingly exposed to an infected person, he 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. In the absence of interoperability between states, travelers must check each state’s rules for quarantine or testing.

In order to have a truly nationwide network of apps that can connect and share data, more states need to step up, Becker said, adding that he was hopeful several states would begin rolling out the technology now that the presidential election is over. Restrictions related to Covid-19 had become a highly political and contentious issue, especially in Republican-majority states, so any attention to tracing apps was largely set aside for the time being.

But contact-tracing apps are only effective if enough people download and use them. That requires a strong push from state officials, as well as media coverage and promotion. The Biden administration’s effort to kickstart a long-overdue national effort means, “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.

Usage tracks the politics

The number of downloads and usage of contact-tracing apps varies by state and roughly seems to match political orientations, with greater participation in Democratic-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, by early November, 743,000 residents had downloaded the state’s COVIDWISE app that was launched in August, said Jeff Stover, executive advisor to the commissioner of Virginia’s Department of Health.

That number represents about 17.5 percent of the target population, which is people between 18 and 65 years of age who own a smartphone, Stover said. The rate of downloads across the state is growing steadily, and Virginia continues to promote the app, he said.

Across the country in conservative North Dakota, the rate of downloads is just 3 percent among the target population, said Tim Brookins, a Microsoft engineer who developed the app for the state. The download rate is higher among populations with higher potential risk of exposure to the coronavirus, he said.

“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.

At the same time, 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 broad promotion to encourage use statewide, the University of Arizona developed and pilot-tested that state’s app and is rolling it out in “defined communities,” Masel said.

The goal is to get higher adoption rates in universities, then expand the use of the app to Native American reservations and large employers in the state, and then to the broader community, Masel said. “That creates a network effect” and avoids potential failures that may come with everyone downloading the app at once, she said.

Echoing Brookins and the North Dakota example, Masel said that in Arizona, where the app is only available in two universities, data collected by manual contact tracers shows that 48 percent of those who test positive for Covid-19 had the app.

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 started exhibiting symptoms, and also send daily prompts to users reminding them to isolate.

The absence of a federal response at the start of the pandemic has led to innovations in multiple states and tech companies like Apple and Google becoming de facto regulators on what kind of data is collected, Masel said.

Instead of trying to override all that with a federal app, 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. Tracing and research could be more effective and efficient, for example, if epidemiologists could use the apps to collect more information such as the onset of symptoms, as Arizona does, and if they could focus most data-collection on large events and gatherings, she said.

Accomplishing such feats will require as much attention by the new Biden administration to the politics as to the technology.