COVIDWISE – Frequently Asked Questions

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Frequently Asked Questions


COVIDWISE is the Virginia Department of Health (VDH) COVID-19 exposure notification app to facilitate contact tracing in response to the coronavirus that causes COVID-19. Contact tracing is a technique used by public health authorities to contact and give guidance to anyone who may have been exposed to a person who has tested positive for COVID-19. This technique will be an essential part of transitioning back to regular daily life while managing the risk of further outbreaks.

How can Exposure Notifications Help?

Traditional methods of contact tracing are critical to containing the spread of infection, but require an infected person to list specific people they may have exposed and places they have been. Technology can support and augment these efforts by allowing public health authorities to notify a larger number of people who the infected person may not have known or remembered to list. This starts with members of the population enabling Exposure Notifications on their smartphones, which enables COVIDWISE to send you a notification if you’ve been near another COVIDWISE user who later tests positive for COVID-19.

Follow this link to learn more.

How does the app work?

COVIDWISE is designed to notify users when they have been in contact with other users that have tested positive for COVID-19.

The app is built on Apple and Google’s Exposure Notification system that allows smartphones to exchange anonymous keys over Bluetooth. These anonymous keys change daily to protect your identity. Each phone shares its own daily anonymous key and stores the anonymous keys of nearby devices locally (i.e. on the user’s phone) for 14 days.

When people who have downloaded the app are near each other for a period of time determined by VDH to represent a risk (a period which is updated based on the latest research), their phones exchange anonymous keys, and each saves the anonymous key of the other phone. Alongside the anonymous key, phones estimate the contact risk of an exchange using the date, time, and the duration of the contact, as well as the strength of the Bluetooth signal (to approximate distance). Contact risk is used to determine if a user is notified of a potential exposure and is not shared with any user.

Do I have to use the app?

No. Download and use of the app is 100% voluntary and you may choose to install and uninstall the app at any time. However, we strongly encourage your participation as it will help improve the overall effectiveness of efforts to prevent the spread of COVID-19 in the community.

Does the app work outside of the state of Virginia?

The app will continue to exchange anonymous keys with other COVIDWISE users that have Exposure Notifications enabled wherever you are, even outside of Virginia. However, any user that chooses to submit a positive diagnosis must be verified with the Virginia Department of Health to receive a PIN to submit in the app. This makes the app much less effective outside of Virginia.

There have been discussions regarding a federal database for positive diagnosis verification which would greatly simplify interoperability of exposure notification apps between states. It is not currently certain when this will be available.

Where can I download COVIDWISE?

COVIDWISE can be downloaded from the App Store for iPhone users and the Google Play Store for Android users. Please note that not all devices are supported.

How is "exposure" determined? Within less than 6 feet? Casual contact without a mask?

See answer to "Does the app use the CDC definition of close contact -- within 6 ft for at least 15 minutes?"

Do the users have to be intentional about putting their phones near each other, or does the connection take place automatically?

The connection happens automatically.


COVID-19 Exposure LoggingI Received a Notification but my Exposures tab says “No Past Exposures.” What was the meaning of that notification?

If your app's Exposure screen still says "No Exposures Detected" then it is likely that the notification you saw was a weekly summary notification. This goes out weekly with text that says (on Android as an example), "Your device identified # potential exposures this week, and shared them with COVIDWISE." The # in that message would be replaced with the number of anonymous tokens from users who tested positive, regardless of whether they met the duration and distance thresholds VDH uses to consider a significant exposure. Your app would still say "No Exposures Detected" if those matched keys didn't add up to greater than 15 minutes of exposure and/or the Bluetooth signal strength of those keys didn't look like they were within 6 feet of you. So according to the app's best estimate based on VDH guidelines, you haven't had a significant exposure, but you may have briefly passed at a distance (even a few times) someone who went on to test positive.

exposure checksWithin Settings I can see several checks, many at the same time. Do these mean I was exposed?

Within your device’s Settings menu, you can see an Exposure Notification or Exposure Logging section (the path to these is slightly different on some devices, but is typically as stated here): Android: Settings > Google > COVID-19 Exposure Notifications iOS: Settings > Privacy > Health > COVID-19 Exposure Logging or Settings>Exposure Notifications Within those menus, you can find an “Exposure checks” field with a timestamped list. These items are not exposures, but rather when your device made the checks against the tokens from positive users that your device has downloaded from the server to look if you have had an exposure. You may see several entries with the same date, as the keys of positive users are separated into a few files, and your device will download and check for matches within each of those files.

If two students are in adjacent dorm rooms with a wall between them does the wall block the Bluetooth or could the person in another room be identified a close contact?

A wall would be expected to diminish the signal strength between devices, but the extent would be determined by the materials and structure of the wall. It is possible that two devices close to a shared wall would still have sufficient signal strength to trigger a notification.

Once a person uploads their positive tests results, how long does their phone/app send out they tested positive? More than 14 days after testing positive?

COVIDWISE only uploads a user’s anonymous tokens for the day of and the 14 days prior to the user submitting a positive report. It will not continue to upload any information unless the user tests positive again and submits another report.

Does the app have a mechanism to indicate when a person has been cleared to return from isolation in case they have been positive but have become well. Is there a PIN to indicate that?

The app only submits a user’s past 14 days of tokens, so there is no need to clear them in the future.

Can you address the 'once a PIN identifies someone as positive, are they always going to show as positive or will they be followed and someone marked as negative appropriately so as not to continue to trigger a 'positive' to other users after they are no longer of concern?

A positive submission is only considered positive for the previous 14 days. A user’s keys after a submission are not uploaded unless the user tests positive again and submits a new report.

If an infected user chooses to notify others in the app, how long will it take to notify those users that they were near?

If a user submits a positive test result in the app to notify others, users that they were near can expect to receive an exposure notification within the next day or so from the time the report was submitted. This time is needed to make the positive user’s tokens available on the server and for other users’ devices to download those tokens & check for potential matches.

Does the app use the CDC definition of close contact -- within 6 ft for at least 15 minutes?

COVIDWISE makes a best effort to use the CDC definition of close contact (within 6 feet for at least 15 minutes) when notifying users of a recent exposure with someone who has gone on to test positive for COVID-19. Because COVIDWISE does not know users’ locations or their positions relative to one another, COVIDWISE estimates distance by evaluating the Bluetooth signal strength (attenuation) between two devices. Researchers have recorded various signal strengths between devices at various distances, and COVIDWISE uses attenuation thresholds to recognize encounters that exhibit attenuation signal strengths researchers have measured when devices are at a distance of 6 feet.

What is the proximity to exposure that will trigger an alert?

See answer to "Does the app use the CDC definition of close contact -- within 6 ft for at least 15 minutes?"

What if people submit false test reports in the app?

To prevent users from submitting false test results, the app requires users to confirm their test result using a verification code provided by VDH. VDH staff contact you over the phone and request the first three letters of your first and last names, and your date of birth to ensure a match with a laboratory report. Once confirmed, VDH will provide you a personal identification number (PIN) that is not tied to your identity. Enter the PIN into COVIDWISE to report your positive test. The app will upload the list of anonymous keys it has been in contact with over the past 14 days only after a test result has been validated.

After receiving test results, how quickly will the phone call be placed?

The individual and VDH should receive test results at about the same time. A VDH case investigator will then reach out to anyone who has tested positive. This typically happens within 24 hours of the test results being available.

How does the app know if I’m infected?

When a person tests positive for COVID-19, the laboratory that conducts their test will submit those results to VDH. VDH will contact this individual to discuss recommended next steps. During that contact, VDH will provide the user a personal identification number (PIN), which is required to submit a positive test result in COVIDWISE to prevent false reporting.

The individual now can choose to use this PIN to report their test result in COVIDWISE. In such cases, the app will send all of this user’s daily anonymous keys from the past 14 days to a server after the infected user has given their consent to share that data.

Every phone that has the app installed regularly downloads the list of anonymous keys for users that have been tested positive. The app then compares that list with the list of anonymous keys it has encountered during the past two weeks. This matching does not happen on a centralized server, but directly on each user’s device. If a match is found, the app uses the duration of the exposure and the strength of the Bluetooth signal to determine if the exposure meets a risk threshold established by latest international research.

If the risk threshold is met, the user will be notified that they have had a possible exposure to someone who has tested positive for COVID-19.

Does the app use any of my personal information?

No. COVIDWISE does not collect, use, or store any personal identifiable information or location data. The app is designed to protect your privacy. Neither your identity nor your location is shared by the app with VDH or other app users.

Does the app use my location?

No. Your location is never used or collected in COVIDWISE. The exposure notification system is based on Bluetooth Low Energy and does not collect any geolocation or GPS data.

How do I get notified if I am exposed to another user who has tested positive for COVID-19?

If the app detects that you've been exposed to another user who has tested positive and chosen to share that with other users in the app, you will receive a push notification to inform you of a potential exposure. You can open the app to view a notice that you have possibly been exposed, along with resources for learning more and guidance on next steps.

Does this app work on older phones?

iPhone users can use COVIDWISE if your iPhone has iOS version 13.5 or above. The following iPhones support iOS 13.5: 11, 11 Pro, 11 Pro Max, Xr, Xs, Xs Max, X, SE (2nd generation), 8, 8 Plus, 7, 7 Plus, 6s, 6s Plus, SE (1st generation).

Android users can use COVIDWISE if your Android smartphone supports Bluetooth Low Energy and Android Version 6 (API 23) or above.

Note that you will not be able to install and use COVIDWISE if your phone does not meet these requirements.

What can I do if my smartphone isn’t supported by COVIDWISE?

We truly appreciate your interest in COVIDWISE. Unfortunately, if your phone does not meet the version requirements, it’s not possible to use the app at this time. COVIDWISE leverages the Exposure Notification interface provided by Apple and Google which determines the requirements for installing and using the app. We understand that this may prevent many people from being able to use COVIDWISE. We will keep the community updated on any changes in these requirements.

Do I have to leave COVIDWISE open at all times for the app to work?

No. COVIDWISE runs in the background and does not need to be open or running to work. You only need to make sure the app is installed, exposure notifications have been enabled, and Bluetooth is turned on.

Do I need to keep Bluetooth turned on at all times for the app to work?

Yes. The exposure notification system is based on Bluetooth Low Energy, so Bluetooth must always be active for the system to detect your contact with other users.

Will COVIDWISE use a lot of data?

No. Every day, the app downloads the new anonymous keys for detecting possible exposures. You can expect this to consume a few megabytes of your data each day.

Will the app drain my battery?

No. COVIDWISE uses Bluetooth Low Energy which is designed to be energy efficient to minimize impact on battery use. Some battery use is required to support this app, but you should not see a significant impact to your battery consumption after installing the app.

Will this app work on iPads?

No, unfortunately the Exposure Notification framework was designed specifically for smartphones and is not supported on iPads or tablets.

Will this work with a smartwatch that is Bluetooth enabled?

No, unfortunately the Exposure Notification framework was designed specifically for smartphones and is not supported on smartwatches.

Do I need to be connected to Wifi or a cellular data connection for COVIDWISE to work?

The exchange of anonymous tokens between users is done over Bluetooth and does not require Wifi or a cellular data connection. As long as Bluetooth is turned on, your phone will continue to exchange tokens with others. However other app functionality, including PIN submission, positive key downloads to receive notifications, and the virtual agent, do require a Wifi or cellular data connection to work.

I am using a device with iOS 13.6 and getting an Error Code 14 upon attempting to enable Exposure Notifications. What can I do?

We had a few users experience this issue, and we worked with Apple to develop a solution. A fix for this issue has been released in iOS update 13.6.1, so please go to Settings > General > Software Update to check if an update is required for your device.

Why does Location need to be enabled on Android devices?

On Android devices, Location needs to be enabled for Bluetooth to work, even though location is not used by the app.

In this blog post, Google discusses this in further detail. It is a feature that Google built into Android back in 2015 to improve user privacy. They did not anticipate that they would ever need EN and bluetooth tech in this way. We realize it creates a lot of confusion since EN absolutely doesn't collect any user location data -- so Google is changing this in the next release of Android.

On an Android device, I get an “Internal error” when attempting to enable Exposure Notifications. How can I fix this?

We have seen this on some Android devices where Google Play services have not been updated. To resolve this, follow these steps:

  1. On your Android phone or tablet, open the Settings app.
  2. Tap “Apps” or “Apps & notifications” then “See all apps.”
  3. Scroll down and tap “Google Play services”
  4. Scroll down and tap “App Details” or “App details in store”
  5. Tap “Update” or “Install”

This should resolve your issue. If it does not, please use our app feedback form to get in touch with us.

Is COVIDWISE open source?

Yes, you can access the source code here,

I turn my phone off periodically, usually a few hours per day to charge and/or reboot it. Does that affect the app?

Yes, this does affect the app only slightly. In other words, this may prevent receipt of anonymous keys updates that allow for the exposure notifications to work effectively if the phone is off when you leave your location.


How does the app support accessibility?

We want to make sure that COVIDWISE can be used by as many people as possible.

COVIDWISE has been designed to meet Web Content Accessibility Guidelines where possible, including layout, sizing, navigation, and color contrast to improve app useability for all users. COVIDWISE is also designed to support smartphone assistive technologies including VoiceOver on iOS and TalkBack on Android for visually impaired users.

We will continue working to identify further accessibility improvements that can be incorporated into COVIDWISE.

What languages are supported in the app?

Currently COVIDWISE supports English and Spanish languages. The app will use the language that is set in your device’s Settings.

Can a symptom check application be added?

VDH has a symptom tracker tool called COVIDCHECK.  You can access it by clicking here.

Can a local health department locator be added?

COVIDWISE currently links to a local health department locator from the Virtual VDH component of the app within the “I received an exposure notification” response.

Does this app include a testing locator?

From the Virtual VDH component in the app, by selecting the “Find more information” response, you can navigate to, which contains a link to a testing locator.