This week, Virginia plans to release a COVID-19 exposure notification app based on the specifications published by Apple and Google in April. The app, called COVIDWISE, is the first fully deployed implementation of Apple and Google’s system in the US and was beta tested by the state department of health.
The specification is designed to preserve patient privacy, particularly around their location and whether they have tested positive for COVID-19. “No location data or personal information is ever collected, stored or transmitted to VDH as part of the app,” a health department official told Virginia Public Media, which first reported the news. “You can delete the app or turn off exposure notifications at any time.”
If someone tests positive for the coronavirus, the Virginia Department of Health (VDH) will give them a PIN number that they can choose to use to report that result within the app. Then, other users of the app should get a notification if their phones were near the sick person at some point in the past 14 days. However, those notifications will only go out to phones when the exposure met a threshold for a strength and duration of the Bluetooth signal that can be estimated as a user being within six feet of the other user for 15 minutes (based on the Centers for Disease Control and Prevention’s definition of “close contact”).
Apple and Google’s system relies on Bluetooth Low Energy (BLE) and does not track physical location through GPS. Instead, it collects and stores signals from nearby phones. Phones trade anonymous keys, which change every 15 minutes. The companies announced their partnership in April and released the system’s API to health departments in May.
Apps that automate the contact tracing process can help flag people who were near someone with COVID-19, even if they may not remember interacting. They can also provide instant notification of a possible virus exposure. But they’re not a replacement for manual contact tracing because they’re only able to monitor the contacts between people who have smartphones and decide to use the app. The VDH said it’s not using the app as part of its own contact tracing process, but that it offers a way for users to track their own potential exposures.
The more people who download the app, the more effective it will be. “If enough of the population downloaded this app and enabled it on their phone, we would have an automated way of figuring out who you have been around,” Danny Avula, director of the Richmond and Henrico health districts in Virginia, told VPM.
Alabama launched a closed pilot for its own exposure notification app, called GuideSafe, this week. The pilot is open to anyone in the state with an .edu email address. It’s part of the state’s return-to-campus plans, said University of Alabama at Birmingham president Ray Watts. The app is aiming for 10,000 downloads each on Apple and Android phones.
Twenty US states are interested in apps that use the Apple and Google system, Google said last week. Alabama, South Carolina, and North Dakota each had projects in development in May. The Association of Public Health Laboratories is also building a national server that will allow apps to work across state lines.