COVID-19 Contact-Tracing Apps

From SI410
Revision as of 21:22, 27 January 2022 by Kjhburke (Talk | contribs)

Jump to: navigation, search
Structures for COVID-19 contact tracing apps.

COVID-19 contact tracing apps are digital platforms designed to help identify and prevent the spread of COVID-19. Their purpose is to automate the contact tracing process in a faster and more reliable way. These mobile applications are not intended to replace existing contact tracing methods, but rather to act as additional support.

Smartphones have been identified as useful devices for contact tracing due to their GPS and Bluetooth capabilities. Additionally, the wide use of smartphones globally has created a relatively accessible way for COVID-19 contact tracing apps to collect data from their users. This data can then be used to help identify people who have been exposed to and possibly infected with COVID-19.[1]

With mobile applications increasingly becoming important tools for combating the spread of the COVID-19 virus, a number of ethical concerns have been discussed. Challenges regarding privacy, equity, and voluntariness have grown common, as these applications rely heavily on user data. However, research has shown that if in line with ethical guidelines, COVID-19 contact tracing apps may serve as an effective tool.

Coronavirus Disease 2019

Coronavirus disease 2019 (COVID-19) is a disease caused by the SARS-CoV-2 virus. It was first discovered in Wuhan, China in late 2019 and has since spread worldwide, resulting in an ongoing pandemic. As of mid-January 2022, there have been 350 million confirmed COVID-19 cases worldwide and 5.5 million reported deaths.[2]

According to the CDC, COVID-19 is very contagious, due to the fact that it is a respiratory virus. It can be quickly transmitted when an infected person breathes, coughs, sneezes, or speaks out droplets that contain the virus. Anyone within 6 feet of an infected individual is at risk of becoming infected.[3]

Symptoms of COVID-19 have been reported to include a wide range, varying from mild to severe illness. People may begin to experience symptoms between 1-14 days after initial exposure. This may include a fever, cough, shortness of breath, fatigue, loss of taste or smell, congestion, and a sore throat. Older populations, as well as those with underlying health conditions, are reported to be at higher risk for developing more severe symptoms of COVID-19.[4] Asymptomatic cases have also been found to be very common among patients, creating further challenges for the pandemic. In a recent study conducted by Duke University, nearly 40% of the children aged 6 to 13 who tested positive for COVID-19 were asymptomatic.[5] As a result, many infected individuals can spread the virus without even knowing it.

Overall, it has become difficult to manage positive COVID-19 cases, due to the large range in symptoms and the ease of spread. In response, public health officials have employed several methods, such as contact tracing, to help mitigate the spread of the disease and protect communities.

Contact Tracing

Contact tracing is a method that has long been used by health departments to minimize contagious diseases. The process aims to identify both the individuals infected as well as the people they have been in close contact with in order to prevent further spread.[6]

Process

The basic process of all contact tracing follows four steps: testing, identification, notification, and monitoring.[7]

Testing

Individuals are generally confirmed to be infected via tests. Tests vary based on the disease for which one is screening. Tests can include blood tests, urine tests, throat swabs, nasal swabs, and spinal taps.[8]

Identification

Infected individuals should identify everyone that they were in close contact with during the period of their contagion. In certain cases, they can include the time before they began experiencing symptoms.

Notification

All contacts are informed of the details of their exposure and advised on how they should proceed. Contacts are often provided resources for how they can protect themselves.

Monitoring

Contacts are followed-up in order to monitor their health. Depending on the circumstance, they are encouraged to self-quarantine if possible and to monitor their own health for a specific time period.

Case Studies

Ebola Epidemic

Contact tracing played a significant role during the 2014-2015 Ebola epidemic. Facing the largest Ebola outbreak in history, Liberia implemented contact tracing efforts in all 15 different counties to help contain the disease.[9] Health workers successfully created a manual system that identified, assessed, and managed people who were exposed to the Ebola virus, preventing further transmission.[10]

HIV

When HIV emerged in the early 1980s, contact tracing quickly became a tool to limit the spread of infection. Several states developed HIV contact tracing programs. These programs, which were often referred to as “partner notification programs,” were and still are completely voluntary.[11] Partner notification programs proved to be an effective method in controlling the transmission of HIV as well as STIs and other infectious diseases.

COVID-19 Response

Contact tracing has become a cornerstone of various public health departments’ responses to the COVID-19 pandemic. Countries have implemented large-scale contact tracing efforts in hopes to decrease the spread of the COVID-19 virus and help protect their communities. In regards to COVID-19, a close contact is considered to be “someone who had face-to-face contact with an infected person within 6 feet for at least 15 minutes.”[12]

Methods

Manual Contact Tracing

Traditionally, contact tracing has been done manually by individual public health officials. When a patient is confirmed to be infected, they will be contacted by the health department to complete an interview with a member of their staff. The staff member will then be responsible for notifying those who have been exposed as quickly as possible as well as following up periodically. Manual contact tracing interviews are generally conducted via phone.[13]

Digital Contact Tracing

Researchers have begun exploring technology-based solutions in order to quickly increase the scale of contact tracing for COVID-19. With the use of Bluetooth and GPS technology, digital applications have presented automated methods of contact tracing. A study conducted by Jonatan Almagor and Stefano Picascia explored the effectiveness of a COVID-19 contact tracing app compared to that of manual methods. When a user of the contact tracing app tested positive for COVID-19, their smartphone notified those who had come into close contact of their potential exposure. The research found that smartphone-based contact tracing was in fact a mitigation strategy worth pursuing, as it not only reduced the spread of the virus but also did so at a faster and more affordable rate.[14]

Kinexon also pursued a digital solution for contact tracing through the creation of their SafeTag. The wearable device “warns users if they are too close to another” in addition to recording the proximity and duration of their exposures.[15] Kinexon’s SafeTags are currently being used by large companies to perform real-time contact tracing in order to help prevent the spread of COVID-19. The NBA and NFL have used the device as part of their procedures to keep players, officials, coaches, and employees safe.[16]

Limitations

Although contact tracing has previously proven to be effective, recent studies have suggested that the procedure may be limited in the face of the COVID-19 pandemic. Delays in testing have complicated contact tracing methods, making it challenging for health systems to keep up.[17]

Limits to Manual Contact Tracing

According to a study done in the UK, manual systems of contact tracing are likely to be overwhelmed as infection rates increase.[18] This is due to a number of reasons, beginning with the fact that manual contact tracing procedures rely on a sizable trained workforce.[19] Manual contact tracing is also very labor intensive and can move very slowly. This method is also limited because it requires infected individuals to cooperate throughout the full interview process. Those who have tested positive may not always be reached and some may not know or be willing to disclose the full details of their close contacts.[20] Additionally, not all people are symptomatic, leaving many positive COVID-19 cases undetected and therefore, untraced.

Limits to Digital Contact Tracing

Digital contact tracing methods are also limited due to several reasons. To start, the effectiveness of a digital solution largely relies on the installation rate in the given area. A study done on Singapore’s app confirmed this when only 20% of the population used the app. The results stated that only 4% of the exposed contacts would have actually been able to be contacted because of the low participation on the app. The study said that digital contact tracing methods become less effective when people are unable to or unwilling to engage with them.[21]

Digital contact tracing methods can also be limited when people do not know how to properly use them. A study conducted on a Japanese COVID-19 contact tracing app said that “only 60.8% of users were using the application correctly.”[22] As a result, this limited the capabilities of the tool. Overall, the effectiveness of COVID-19 contact tracing apps increases when more users download, register, and actively use it.

App Structures

COVID-19 contact tracing apps follow either a centralized or decentralized structure. These structures primarily differ in their storage methods as well as their data collection process.

Centralized Structure

A centralized contact tracing app collects data through a central server owned and operated by government bodies, such as public health departments. The server processes the data received and informs necessary users about their exposures.[23] Examples of centralized contact tracing apps include Singapore’s TraceTogether application.

Decentralized Structure

A decentralized contact tracing app gives users more privacy by allowing them to have control over their information.[24] Data is stored on an individual’s device, such as a mobile phone, which will alert them when they are at risk for infection.[25] Examples of decentralized contact tracing apps include Apple and Google’s Exposure Notification system.

Ethical Concerns

Although COVID-19 contact tracing apps have proven to be effective, there are still some ethical concerns that have prevented a high degree of adoption.

Privacy

The emergence of COVID-19 contact tracing apps has created issues surrounding users’ privacy. These applications require a certain amount of user data, such as location, in order to accurately track COVID-19 exposures. Users have found that many applications have vague privacy and data management policies. In fact, some applications do not share them at all. This is particularly concerning in centralized COVID-19 contact tracing applications because this structure allows governing bodies to access personal information about all of its users. Centralized apps are also at a higher risk of a data breach, as hackers or other individuals may try to gain control of the data.[26]

Equity

Equity is an ethical concern in regards to COVID-19 contact tracing apps due to the fact that the required technology is not available to everyone. Although the use of mobile phones has spread rapidly around the world, there are still disparities between those who do and do not have access to tools such as the internet and GPS or Bluetooth-capable devices. A study conducted by Pew Research Center found that smartphone ownership was higher in places with advanced economies than emerging. Additionally, those with higher education, whether in advanced or emerging economies, were also more likely to have access to mobile devices.[27] As a result, there are concerns that COVID-19 contact tracing apps will disproportionately benefit certain populations.

Voluntariness

Voluntariness can be defined as a decision or action made free from coercion or influence by outside parties.[28] Voluntariness becomes an ethical concern in regards to COVID-19 contact tracing apps when it is not protected. An application that protects voluntariness makes each step of the digital contact tracing process voluntary. This includes the user’s decision to download the application, enroll in alerts, and share contacts after testing positive.[29] Voluntariness also requires that adequate information is provided to the user about the application so that they can make well informed decisions.

Best Practices

Based on the ethical concerns that have been identified in response to the release of COVID-19 contact contracting applications, general guidelines have been suggested for the ideal platform.

Decentralized Privacy Protocol

The University of Michigan Center for Ethics, Society, and Computing recommends that all COVID-19 contact tracing applications should follow a decentralized structure in order to minimize chances for mistreatment or data breaches.[30]

Anonymized Data

The University of Michigan Center for Ethics, Society, and Computing recommends that all data collected should be left anonymous to protect the privacy of users. Such data, including health and location, should be disassociated with any personally identifiable information.[31]

Accessible

According to Jeffrey Kahn, director of the Johns Hopkins Berman Institute of Bioethics, “policies should make sure that access to the technology and its benefits, as well as the distribution of its burdens, are shared equitably.”[32] Since digital contact tracing has been proven to offer a benefit, it is important that a COVID-19 contact tracing app is accessible for everyone within its targeted population.

Voluntary

A study published by JMIR mHealthAll suggests that steps of the application should be voluntary and consent-based. The application should maintain full transparency with users by making information about data use, protection, and privacy publicly available.[33] Users should always have the ability to opt out of participation at any time without consequence.

Post-Pandemic Protocol

The University of Michigan Center for Ethics, Society, and Computing recommends that once the COVID-19 pandemic has been declared to be over, all data should be destroyed. This applies to both centralized and decentralized applications, meaning that information should be erased from local devices as well as government-controlled storage.[34] Users should also be given instructions on how to delete the application from their personal devices.

List of Apps

In response to the COVID-19 pandemic, dozens of countries and states have released various contact tracing apps to alert citizens of exposures. A number of examples have been detailed below.

TraceTogether

TraceTogether is a mobile application used in Singapore aimed to minimize the spread of COVID-19. The platform uses Bluetooth to determine when other users are nearby and notifies them if they have been exposed to the virus. TraceTogether was one of the very first COVID-19 contact tracing applications to be launched and was installed by 20 percent of Singapore’s population after just one month.[35] The application attracted the interest of many other governments looking to adopt similar tools.

CA Notify

CA Notify is a free-to-use service that informs users if they have been exposed to COVID-19. Developed by the California Department of Public Health, the application relies on Bluetooth technology to alert users if they were in close contact with someone who has tested positive. Users can use the services to anonymously report their positive COVID-19 cases as well as to track their symptoms. The service is 100% voluntary and does not track personally identifiable information.[36]

NHS COVID-19

The National Health Service (NHS) COVID-19 is a contact tracing application for England and Wales. The application offers a variety of features, including contact tracing, COVID-19 resources, and local restrictions. In February 2021, researchers confirmed that the NHS COVID-19 application was successful in helping reduce the number of infections.[37]

Apple & Google’s Exposure Notification System

Apple and Google have partnered together to develop the Exposure Notification System that is available for all Android and iOS devices. The purpose of the technology is to aid governments in the protection of local communities against the spread of COVID-19. The Exposure Notification System relies on Bluetooth technology to track exposures and alert users when necessary.[38]

MI COVID Alert

MI COVID Alert is a COVID-19 exposure notification application developed by the Michigan Department of Health and Human Services (MDHHS). The platform uses Bluetooth Low Energy (BLE) in collaboration with Apple and Google’s API to notify Michigan residents of COVID-19 exposures. It is completely voluntary and follows a decentralized structure, protecting users’ privacy and data.[39]

COVID Alert

COVID Alert is Canada’s free contact tracing application. Using Bluetooth, the app alerts users of possible exposures, even before they may begin experiencing virus-related symptoms. As of January 1, 2022, the application has been downloaded by 6.8 million Canadians and is available to 9 provinces and territories.[40] COVID Alert has maintained full transparency with its users, by keeping the source code and privacy policy public.

COVIDSafe

COVIDSafe is the Australian Government’s coronavirus app released on April 26, 2020. The application uses Bluetooth technology to anonymously take note of other app users people come in contact with. COVIDSafe has a decentralized structure, keeping all data encrypted and stored locally on each users’ device. When exposed, users will be notified with steps on how to stay safe. COVIDSafe has over 7 million registered users.[41]

Rakning C-19

Rakning C-19 is the official contact tracing application for Iceland. The app tracks when users are in close proximity to one another and warns of possible exposures. If an individual is exposed, the application will provide instructions for how they may get tested. Rakning C-19 is backed by the Civil Protection Unit.[42]

HaMagen

HaMagen is Israel’s contact tracing app supported by the Ministry of Health. The application uses the GPS history of users’ phones and cross-checks it with the geographic data of COVID-19 patients from the Ministry of Health. In the event of a match, HaMagen will send users resources on how to stay safe. The application operates on a decentralized system and on an open source code.[43]

Covid Watch

Covid Watch is the exposure notification application for the state of Arizona. Developed by WeHealth, the application is a privately owned platform that follows a decentralized structure. It was an early adopter of the Google Apple Exposure Notification API and continues to work with both companies in order to ensure users’ data remains protected. Covid Watch was proven to be successful after the University of Arizona saw a nearly 11% reduction rate on campus.[44] The university had included Covid Watch as part of their campus safety protocols.

References

  1. ↑ Ahmed, N., Michelin, R. A., Xue, W., Ruj, S., Malaney, R., Kanhere, S. S., Seneviratne, A., Hu, W., Janicke, H., & Jha, S. K. (2020). A Survey of COVID-19 Contact Tracing Apps. IEEE Access, 8, 134577–134601. https://doi.org/10.1109/ACCESS.2020.3010226
  2. ↑ Coronavirus (COVID-19). (2022, January 23). Google News. https://news.google.com/covid19/map?hl=en-US&gl=US&ceid=US:en
  3. ↑ CDC. (2020, February 11). Covid-19 and your health. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/your-health/about-covid-19/basics-covid-19.html
  4. ↑ Coronavirus disease (COVID-19). (2021, May 13). https://www.who.int/news-room/questions-and-answers/item/coronavirus-disease-covid-19
  5. ↑ Hurst, J. H., Heston, S. M., Chambers, H. N., Cunningham, H. M., Price, M. J., Suarez, L., Crew, C. G., Bose, S., Aquino, J. N., Carr, S. T., Griffin, S. M., Smith, S. H., Jenkins, K., Pfeiffer, T. S., Rodriguez, J., DeMarco, C. T., De Naeyer, N. A., Gurley, T. C., Louzao, R., … Kelly, M. S. (2020). Sars-cov-2 infections among children in the biospecimens from respiratory virus-exposed kids (Brave kids) study. MedRxiv, 2020.08.18.20166835. https://doi.org/10.1101/2020.08.18.20166835
  6. ↑ Phdmc |—What is contact tracing? (2021, August 13). https://www.phdmc.org/coronavirus-updates/364-what-is-contact-tracing
  7. ↑ Bode, M., Leopoldseder, M., Rutten, P., & Wilson, M. (2020, May 8). Contact tracing for COVID-19: New considerations for its practical application | McKinsey. McKinsey & Company. https://www.mckinsey.com/industries/public-and-social-sector/our-insights/contact-tracing-for-covid-19-new-considerations-for-its-practical-application
  8. ↑ Infectious diseases—Diagnosis and treatment—Mayo clinic. (n.d.). Mayo Clinic. Retrieved January 27, 2022, from https://www.mayoclinic.org/diseases-conditions/infectious-diseases/diagnosis-treatment/drc-20351179
  9. ↑ Swanson, K. C., Altare, C., Wesseh, C. S., Nyenswah, T., Ahmed, T., Eyal, N., Hamblion, E. L., Lessler, J., Peters, D. H., & Altmann, M. (2018). Contact tracing performance during the Ebola epidemic in Liberia, 2014-2015. PLOS Neglected Tropical Diseases, 12(9), e0006762. https://doi.org/10.1371/journal.pntd.0006762
  10. ↑ Saurabh, S., & Prateek, S. (2017). Role of contact tracing in containing the 2014 Ebola outbreak: A review. African Health Sciences, 17(1), 225–236. https://doi.org/10.4314/ahs.v17i1.28
  11. ↑ Reflections on the history of contact tracing. (2020, July 13). O’Neill. https://oneill.law.georgetown.edu/reflections-on-the-history-of-contact-tracing/
  12. ↑ Contact tracing can help slow the spread of covid-19 | washtenaw county, mi. (2021, November 10). https://www.washtenaw.org/3170/Contact-Tracing
  13. ↑ Raskar, R., Dhillon, R., Kapa, S., Pahwa, D., Falgas, R., Sinha, L., Prasad, A., Singh, A., Nuzzo, A., Iyer, R., & Sharma, V. (2020). Comparing manual contact tracing and digital contact advice. https://arxiv.org/abs/2008.07325v1
  14. ↑ Almagor, J., & Picascia, S. (2020). Exploring the effectiveness of a COVID-19 contact tracing app using an agent-based model. Scientific Reports, 10(1), 22235. https://doi.org/10.1038/s41598-020-79000-y
  15. ↑ Protect your employees and business operations. (n.d.). Kinexon. Retrieved January 25, 2022, from https://kinexon.com/technology/safetag/
  16. ↑ Golden, J. (2020, July 21). Here’s the device the NFL and NBA are using for coronavirus contact tracing and social distancing. CNBC. https://www.cnbc.com/2020/07/21/nfl-nba-to-use-safezone-tags-for-coronavirus-contact-tracing.html
  17. ↑ Olivo, A. (2022, January 7). Amid omicron surge, contact tracing is more complicated, officials say. Washington Post. https://www.washingtonpost.com/dc-md-va/2022/01/07/omicron-contact-tracing-covid-surge/
  18. ↑ Keeling, M. J., Hollingsworth, T. D., & Read, J. M. (2020). Efficacy of contact tracing for the containment of the 2019 novel coronavirus (COVID-19). Journal of Epidemiology and Community Health, 74(10), 861. https://doi.org/10.1136/jech-2020-214051
  19. ↑ Shahroz, M., Ahmad, F., Younis, M. S., Ahmad, N., Kamel Boulos, M. N., Vinuesa, R., & Qadir, J. (2021). COVID-19 digital contact tracing applications and techniques: A review post initial deployments. Transportation Engineering, 5, 100072. https://doi.org/10.1016/j.treng.2021.100072
  20. ↑ Lewis, D. (2020). Why many countries failed at COVID contact-tracing—But some got it right. Nature, 588(7838), 384–387. https://doi.org/10.1038/d41586-020-03518-4
  21. ↑ Kleinman, R. A., & Merkel, C. (2020). Digital contact tracing for COVID-19. CMAJ : Canadian Medical Association Journal, 192(24), E653–E656. https://doi.org/10.1503/cmaj.200922
  22. ↑ Machida, M., Nakamura, I., Saito, R., Nakaya, T., Hanibuchi, T., Takamiya, T., Odagiri, Y., Fukushima, N., Kikuchi, H., Amagasa, S., Kojima, T., Watanabe, H., & Inoue, S. (2021). Survey on usage and concerns of a COVID-19 contact tracing application in Japan. Public Health in Practice, 2, 100125. https://doi.org/10.1016/j.puhip.2021.100125
  23. ↑ Ciucci, M., & Gouardères, F. (2020). National COVID-19 contact tracing apps. European Union. https://www.europarl.europa.eu/RegData/etudes/BRIE/2020/652711/IPOL_BRI(2020)652711_EN.pdf
  24. ↑ Tanaka, N., Ramachandran, G., & Krishnamachari, B. (2020). Poster: Centralized vs. Decentralized contact tracing: do gdp and democracy index influence privacy choices? 2020 IEEE/ACM International Conference on Connected Health: Applications, Systems and Engineering Technologies (CHASE), 14–15. https://doi.org/10.1145/3384420.3431777
  25. ↑ Ciucci, M., & Gouardères, F. (2020). National COVID-19 contact tracing apps. European Union. https://www.europarl.europa.eu/RegData/etudes/BRIE/2020/652711/IPOL_BRI(2020)652711_EN.pdf
  26. ↑ Hoffman, A. S., Jacobs, B., van Gastel, B., Schraffenberger, H., Sharon, T., & Pas, B. (2021). Towards a seamful ethics of Covid-19 contact tracing apps? Ethics and Information Technology, 23(1), 105–115. https://doi.org/10.1007/s10676-020-09559-7
  27. ↑ Silver, L. (2019, February 5). Smartphone ownership is growing rapidly around the world, but not always equally. Pew Research Center’s Global Attitudes Project. https://www.pewresearch.org/global/2019/02/05/smartphone-ownership-is-growing-rapidly-around-the-world-but-not-always-equally/
  28. ↑ Agrawal, M. (2003). Voluntariness in Clinical Research at the End of Life. Journal of Pain and Symptom Management, 25(4), 25–32. https://www.jpsmjournal.com/article/S0885-3924(03)00057-5/pdf#:~:text=What%20is%20Voluntariness%3F,is%20given%20under%20illegitimate%20pressure.
  29. ↑ Klar, R., & Lanzerath, D. (2020). The ethics of COVID-19 tracking apps – challenges and voluntariness. Research Ethics, 16(3–4), 1–9. https://doi.org/10.1177/1747016120943622
  30. ↑ Esc best practices for pandemic apps at us universities. (2020, August 25). UM ESC. https://esc.umich.edu/pandemic-apps/
  31. ↑ Esc best practices for pandemic apps at us universities. (2020, August 25). UM ESC. https://esc.umich.edu/pandemic-apps/
  32. ↑ May 26, S. V. / P. & 2020. (2020, May 26). Digital contact tracing poses ethical challenges. The Hub. https://hub.jhu.edu/2020/05/26/digital-contact-tracing-ethics/
  33. ↑ O’Connell, J., Abbas, M., Beecham, S., Buckley, J., Chochlov, M., Fitzgerald, B., Glynn, L., Johnson, K., Laffey, J., McNicholas, B., Nuseibeh, B., O’Callaghan, M., O’Keeffe, I., Razzaq, A., Rekanar, K., Richardson, I., Simpkin, A., Storni, C., Tsvyatkova, D., … O’Keeffe, D. (2021). Best practice guidance for digital contact tracing apps: A cross-disciplinary review of the literature. JMIR MHealth and UHealth, 9(6), e27753. https://doi.org/10.2196/27753
  34. ↑ Esc best practices for pandemic apps at us universities. (2020, August 25). UM ESC. https://esc.umich.edu/pandemic-apps/
  35. ↑ Tracetogether. (2021, March 11). https://www.tracetogether.gov.sg
  36. ↑ CA Notify—California can stop the spread. (n.d.). Retrieved January 25, 2022, from https://canotify.ca.gov
  37. ↑ The NHS COVID-19 app support website. (n.d.). Nhs.Uk. Retrieved January 25, 2022, from https://www.covid19.nhs.uk/
  38. ↑ Exposure notifications: Helping fight covid-19 - google. (2020, April). Exposure Notifications: Helping Fight COVID-19 - Google. https://www.google.com/intl/en_us/covid19/exposurenotifications/
  39. ↑ Coronavirus—Why use the app. (n.d.). Retrieved January 25, 2022, from https://www.michigan.gov/coronavirus/0,9753,7-406-99891_102592_102593---,00.html
  40. ↑ Canada, H. (2021, August 12). Download COVID Alert: Canada’s exposure notification app [Education and awareness;navigation page]. https://www.canada.ca/en/public-health/services/diseases/coronavirus-disease-covid-19/covid-alert.html
  41. ↑ COVIDSafe app. (2021, November 8). Australian Government of Public Health. https://www.health.gov.au/resources/apps-and-tools/covidsafe-app
  42. ↑ The Rakning C-19 app. (n.d.). Retrieved January 25, 2022, from https://www.covid.is/app/en
  43. ↑ Hamagen—The ministry of health app for fighting the spread of coronavirus. (n.d.). Retrieved January 25, 2022, from https://govextra.gov.il/ministry-of-health/hamagen-app/download-en/
  44. ↑ Covid watch az exposure notification app | gaen app. (n.d.). Retrieved January 25, 2022, from https://www.wehealth.org/arizona
Retrieved from "http://si410wiki.sites.uofmhosting.net/index.php?title=COVID-19_Contact-Tracing_Apps&oldid=104968"