iPhones and Android devices contain constantly changing anonymous codes that ping nearby phones via Bluetooth — a process that starts once the user opts to get the notifications.
For the exposure notifications to be effective, Android users must turn on Bluetooth and download their state’s Covid-19 notification app. On iPhones, the system is already baked into settings, although users must go to exposure notifications and make sure availability alerts are on.
When someone who uses the feature tests positive for coronavirus, he or she gets a PIN from a health official to enter into their phone. Any other phone that was nearby in the previous two weeks — usually within six feet or less, for at least 15 minutes — will get an alert telling the user to quarantine and notify a health provider.
The apps assess your risk on the strength of the Bluetooth signal (how close you were to the other person) and the duration of your contact with them.
Where you can get them
At least 15 states are taking part in this Covid-19 exposure notification system.
Some states reported a flurry of sign-ups within weeks of launching the program. Maryland launched its notification system on November 10 and more than 1 million people have already signed up, said Charlie Gischlar, a spokesman for the state health department. He described the app as “a complement to traditional contact tracing and another tool in the toolbox” to combat coronavirus infections.
“We are at a pivotal moment in this pandemic, and opting in to this service helps keep our families and communities safe and our economy running,” Colorado Gov. Jared Polis said in a statement.
Questions about privacy
Is information from the apps anonymous? Experts say it is.
The apps don’t collect data on users or their locations, and there is no way to link Covid diagnoses and alerts to names and identities on phones, Gischlar said.
“The process is entirely anonymous and doesn’t collect any personally identifiable information, addressing the privacy concerns of earlier more invasive contact tracing apps.”
Earlier versions that sparked privacy concerns were created by third-party developers. This coronavirus notificiation alert technology is provided by Apple and Google, and users can opt out from using it at any time, Gischlar said.
The alerts can reduce Covid-19 infections
The more people who sign up for the alerts, the more effective they are. Right now only a small percentage of the roughly 100 million Americans who live in the 15 states use the apps.
For example, New York, New Jersey, Pennsylvania and Delaware have formed a regional alliance that uses a similar system that allows their apps to work across state lines, Anscombe said.
States face some challenges in spreading them
The alert system is designed to complement traditional contact tracing, not work alone.
But technology brings its own set of challenges. For starters, the notification system only works on Google and Apple phones that are less than five years old, Anscombe said. Not everyone has a newer smartphone, and only a small percentage of those who do are using the notification system.
In addition, not all states are using the notification system. Many state health departments are already overwhelmed by the virus’ resurgence, and some may not have the resources to develop and maintain an app, Anscombe said.
The earlier, GPS-based notification system caused an outcry among privacy advocates and has created skepticism about contact tracing in general, Waters said.
“States need additional funding, currently stuck in Congress, to help battle disinformation and increase adoption of this critical tool in the battle against Covid,” Waters said.