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Frequently Asked Questions

What is an exposure notification app and how does it help battle the pandemic and COVID-19?

General FAQ

What is contact tracing?

Contact tracing is the process of reconstructing the interactions of a sick person from the time they were infected until the time they were diagnosed. A case investigator reaches out to a person who has tested positive and helps them create a list of contacts they've recently been close to, who may have been exposed. Their contacts are then notified about their potential exposure and are given recommendations to help slow down the spread of the virus.

Contact tracing has typically been done manually. Manual contact tracing is a proven method and is highly effective. However, it requires a lot of time and resources. New tools can help scale and supplement manual contact tracing, such as digital contact tracing and exposure notification technology, like this app.

How do app-based anonymous exposure notifications differ from contact tracing?

Contact tracing relies on personal data to track where you’ve been and whom you have been in contact with in order to determine your individual exposure level. The app is completely anonymous. It does not collect or share any personal identifying information or location data and instead works off of exchanging random anonymous IDs with smartphones near you who have Exposure Notifications enabled and are using Bluetooth.

How do exposure notifications help to stop the spread of COVID-19?

Individuals can spread COVID-19 before symptoms develop. If we can notify those who have been exposed, they can get tested and stay home without spreading the disease to others. If you are exposed to COVID-19 or if you test positive for COVID-19, the app will provide custom recommendations tailored to your community, including putting you in touch with people who can help.

Does everyone need to use the app for it to work?

The app works best when communities adopt it together, but it’s not necessary for everyone around you to have it installed to help slow the spread of COVID-19. Even if a relatively small percentage of a community is using the app, it can still help slow down the spread. In general, each additional person using the app increases the speed with which individuals can act on information about their exposure risk and the steps they can take to keep their communities safer.

What is the difference between COVID Watch Arizona and WeHealth Arizona?

As of March 2022, the Covid Watch Arizona app is now called WeHealth Arizona. Along with timely, relevant, and actionable health information to help you keep yourself and your community safe, the app will continue to evolve as we adapt to the new normal.

How it Works

Will the notifications tell me where and when I was exposed?

Since we choose not to collect any location data due to privacy concerns, we don't use GPS, so we can’t tell you where you were exposed. However, we will be able to tell you on which day you were exposed.

We recognize that this involves some privacy trade-offs, since if you receive an alert that you were exposed on a day where you were within six feet of very few people, you may be able to deduce who shared their test results.

We think the benefits of knowing when you were exposed outweigh the privacy risks of deduction. Anyone concerned about deduction can choose not to share their diagnosis. Everyone is in full control of what is shared and when.

How is risk calculated?

Risk is based on how close you were to an infected person for how long. Distance is estimated from the strength of the Bluetooth signal that your phone detected coming from their phone. The closer the phones, and the fewer the barriers between them, the stronger the signal detected. Having a phone in a bag or back pocket can cause your phone to overestimate distance and so underestimate risk. The closer you are to an infected person, the higher the risk.

Risk is also based on how Infectious the person was on the day you were in contact, i.e. how much virus they were likely shedding. The most dangerous period is around the time that symptoms begin, and includes days before the infected person has any symptoms at all.

There are other risk factors that the app cannot measure, including whether either of you were wearing a mask, were singing/yelling vs. not talking at all, or were indoors vs. outdoors.

The Google/Apple system combines all contacts you had with one or more infected people, from midnight to midnight in Coordinated Universal Time (UTC). This is why My Exposure Summary in your app might show exposures that don’t quite line up with calendar dates in your local timezone.

Based on your risk, you will be given actionable information for next steps. For example, low risk actionable information may recommend that you “monitor your symptoms for the next 14 days and call this public health number 555-555-5555 for a free test if you develop any symptoms”. High risk actionable information may recommend that you “quarantine away from your family/roommates for 14 days and get tested around day 7”. What the thresholds are for low risk and high risk, and what information you are given, will depend on which community you select - these are set by your local public health authority. You can learn more about how we assess risk in this blog post.

How can you be sure that the diagnosis reports are genuine?

It’s important that users of the app not be able to send out false positives. In order to share a positive diagnosis in the app, you need to use a secure code that can only be generated by your doctor (using the Doximity app), your public health official, or a partnering laboratory that performed your test (e.g. Sonora Quest, LabCorp, or Paradigm Labs).

Privacy and Security

How does the app protect my privacy?

In short, we don't collect data about who you are, where you go, or who you're near. With the app, your phone periodically sends out what we call Bluetooth chirps, essentially saying to nearby phones, “Hey, I'm here!” If another phone is nearby chirping, “Hey, I'm here too,” both phones will log the interaction and store it for 2 weeks right there inside your device. After 2 weeks, the interaction is permanently deleted.

If you are diagnosed with COVID-19, you can choose to share your test results with the app after they are verified by local health officials. Once you do that, you input a random number into the app. Immediately, other devices that have recently heard your phone’s Bluetooth chirps will be alerted to a positive result. The alert contains no personal information and no locations. If a hacker broke into the app, they would just find a bunch of random numbers.

Why does the Android app ask for location permission?

Devices that run on the Android operating system require location permissions for the apps that access Bluetooth. This is because some apps may use Bluetooth to infer user location.

However, apps using GAEN (Google Android Exposure Notification) are unable to access your location data and even access to Bluetooth is only limited to the anonymous exchange of random IDs.

Who gets access to the information I share with the app?

The only information users can share with the app is a positive diagnosis. Sharing your positive diagnosis with the app is completely voluntary. If you do decide to share it, the information will never leave your phone. The only information that will leave your phone is the log of randomly generated keys that your smartphone has been emitting via Bluetooth as part of the Exposure Notification system for the last 14 days. These keys do not encode any personally identifying information or location data and have no meaning outside of the phones with which you have come into close range of while both phones had Bluetooth enabled and Exposure Notifications turned on.

The app also collects anonymous usage statistics. These statistics do not contain any personally identifying information or location data either, and will never be shared outside of the app without your explicit permission. Learn more about Share App Use Statistics here.

How are you sure I can’t be identified when I share my test results?

We can’t identify you because we have never collected information about who you are or where you have been. The communications between phones do not contain any information about who these phones belong to. Our app does not collect personally identifiable information (PII). Exposure notifications can only be generated using a combination of random numbers and the Bluetooth chirps stored on your phone.

Working Together

I am a government, public health, or university official and would like to work with WeHealth. How can I get started?

The app is designed for a speedy implementation using the latest best practices from experts all over the world. We can launch in an entire state or a country in less than 4 weeks while offering community-specific messaging so each city, county, or large campus can personalize the experience for their community, all in the same live app. If you would like to partner with us, request a meeting with our team to learn more.

What is the Google Apple Exposure Notification System (GAEN)?

Apple and Google made a rare joint announcement in April 2020: these two competitors would be working together on creating systems to allow for something they called privacy-preserving exposure notifications’, which is now commonly referred to as GAEN (Google/Apple Exposure Notifications).

Apple and Google responded to challenges Covid Watch and others faced in building a privacy-protecting app to notify communities and individuals of potential exposure to COVID-19.

Read more about Apple and Google’s commitment to privacy here.

Are you working with governments?

WeHealth is a Public Benefit Corporation that develops, implements, and supports exposure notification apps for national and state governments, and that also works with public health authorities at the county, city, tribe, and university level.

We are not a government agency. Our mission is to build mobile technology to fight the pandemic while defending digital privacy and promoting equity. The COVID-19 pandemic presents a once-in-a-lifetime challenge to society, and we hope to help public health emerge stronger by the end.

We work closely with both public health and healthcare partners to verify test results and to make the work of manual contact tracers easier.


View the full FAQ on our Support page