Final Report - COVID Alert as a Public Health Tool

Message from the Co-Chairs

In the wake of the COVID-19 pandemic, Canada joined other nations in leveraging technology developed by Google and Apple to implement COVID Alert, a national exposure notification app available for download across Canada. COVID Alert was offered as part of the measures taken by the Government of Canada to limit the spread and prevent further harmful effects of the virus within the Canadian population.

Per our terms of reference, the Council followed the implementation and oversaw the work and activities carried out since the launch of the app to ensure that it met the highest standards in privacy, technology and public health outcomes. For this, we examined, identified and provided advice on the accessibility, uptake, usage, effectiveness and utility of the app as government service and public health tool.

Despite the government’s efforts to increase the adoption and use of the app and the actions taken to improve it, the Council acknowledges that several challenges persisted which prevented the app from reaching its full potential, in particular with regard to: pan-Canadian participation; app usage; distribution and use of one-time keys (OTKs), and technical limitations on certain smartphones.

Notwithstanding this, we applaud the more than 6.9 million Canadians who downloaded the app and the app users who tested positive and entered an OTK to notify others of a possible exposure hence protecting their loved ones and their communities. We also want to thank the provincial and territorial jurisdictions and their dedicated public health professionals that adopted the COVID Alert app, providing their residents with another tool to help limit the spread in their respective communities.

We are confident that all levels of government will examine and reflect on lessons learned to offer improved digital tools in response to future pandemics or health-related crisis.

Executive summary

Throughout the pandemic, the COVID-19 Exposure Notification App Advisory Council provided advice and guidance to the Government of Canada on COVID Alert. Following the publication of Council’s first and second interim reports, this third and final report concludes the work of the Advisory Council and examines COVID Alert as a public health tool. We endeavor to provide advice and guidance on the integration and application of COVID Alert, as an exposure notification app, situated in a broader public health context over the course of Council’s mandate.

The COVID Alert app was created to be accessible to as many Canadians as possible to help fight the spread of COVID-19. The exposure notification framework on which it was built was intended to be faster than traditional contact tracing methods in reaching a greater number of people who were potentially exposed to the novel coronavirus. While it was not meant as a replacement, the app was to complement and enhance traditional methods of manual contact tracing.

The Council recognizes that COVID Alert was unable to reach its full potential due to technological, adoption, process, resource and individual level factors. Although some provinces and territories (PTs) did attempt to improve their processes for the distribution of OTKs, efforts were limited by resources and did not lead to significant improvements from a user perspective. Assessing the efficacy of the app is difficult given the data-limiting privacy framework upon which the app was built. Nonetheless, COVID Alert has proven to be a way to leverage technology to help fight a global pandemic and offered the Government of Canada a valuable roadmap and lessons learned related to the provision of digital public health services.

While COVID Alert’s usage remains limited, the Council believes that the development of such an app can help inform how digital government services can be improved to provide Canadians and public health professionals with better tools when dealing with future public health crises.


For the first time in history, ubiquitous digital tools were made available by national and sub-national governments to support public health efforts in this worldwide health crisis. In response to the pandemic, G7 members (Canada, France, Germany, Italy, Japan, United States, United Kingdom) and many other countries developed mobile apps as digital public health tools to complement traditional public health practices to augment the fight against COVID-19. While some countries opted for contact tracing apps, Canada followed a privacy-first model, choosing to develop an exposure notification app that did not collect or use personal information regarding the user.

The Council was tasked with a one-year mandate to ensure that COVID Alert met the highest standards in public health outcomes, privacy and technology. The Council’s advice and findings have been captured in three reports:

Pillar 1: Social and Economic Determinants of App Adoption, Retention and Use

  • Increased Accessibility
  • Reduced Barriers to adoption, retention and proper use

Pillar 2: COVID Alert as a Government Service

  • Brand trust for Canadians nationwide
  • Positive experience for app users
  • Leveraging of emerging digital solutions

Pillar 3: COVID Alert as a Public Health Tool

  • Integration of the app into the broader context of the public health system
  • Effectiveness of the app
  • Lessons learned

Since its implementation, the app has been regularly updated to strengthen its performance including narrowing the exposure notification to when the user is at their most infectious state, provide the ability to turn the app on and off, and clear the exposure state in order to receive new risk of exposures.

The app was developed under tight timelines, with the limited information that was available early in the pandemic, and without the benefit of knowing how COVID-19 would play out in Canada and around the world. The acquired knowledge and lessons learned that could not have been accounted for during the app’s development and implementation, can be leveraged to inform how digital tools can offer beneficial public health services in the future.

Pillar Three: COVID Alert as a Public Health Tool

COVID Alert was among the first digital tools of its kind launched, in Canada, during the pandemic to help citizens take action to keep their families, friends, and communities safe. The Council agrees that COVID Alert’s potential has not yet been fully leveraged and concludes that under the right conditions, a digital tool such as COVID Alert can positively impact the fight against a pandemic while supporting the public health community. The Public Health Agency of Canada also continues to see the potential to leverage the lessons learned from this experience toward developing of other digital tools to support public health responses to infectious diseases.

When COVID Alert was rolled-out, Canadians and public health professionals were unaccustomed to using digital tools designed to protect public health. Ideally, a change process such as this one would occur in a calm steady-state context, to ensure that those affected by the change have the time and resources to devote to integrating it. Bringing in a new technological process (i.e. the distribution of OTKs) when contact tracers and case managers were often overwhelmed by case numbers and juggling new reporting databases represented a significant challenge for public health units across the country.

In addition, for the app to function optimally, part of the challenge was to not only ask Canadians to download the app, but to change their behaviors for monitoring their own health. For Canadians coping with a positive COVID-19 test result, being asked to leverage a new digital technology to alert others of a potential exposure to the highly contagious virus imposed new expectations at a stressful time. Learning from the willingness and extent to which Canadians used the app, and the degree to which they voluntarily modified their social interactions during a public health emergency will inform future development of digital tools to support future public health needs.

Measuring the Effectiveness of the App

Given the decision to have a privacy-centric design for COVID Alert, limited metrics were available at launch. Notwithstanding, the Council maintains that the privacy-first approach of the app was the appropriate approach to protect individuals’ privacy in the Canadian context. While there remains some skepticism on the privacy-preserving aspect of the app, the Council recognizes that all levels of government upheld their commitment to maintain Canadians’ privacy, even to the detriment of the ability to fully measure its efficacy or to layer on additional uses beyond the core exposure notification functionality.

COVID Alert was updated in February 2021 to collect metrics, in a privacy protecting manner, at the aggregate level to better understand the app’s use and impact on the pandemic. Beyond the existing data collected since the launch of the app that focused on the overall number of downloads and OTKs generated by provinces/territories that were entered by app users, the February update allowed the collection of additional metrics including:

  • Number of notifications per OTK entered;
  • Number of notifications triggered; and,
  • Number of notifications leading to a positive case.

COVID Alert Metrics

Number of downloads (as of May 31, 2022)6,951,575
Number of OTK entered (as of May 31, 2022)63,117
Average number of notifications issued per OTK entered (February 25, 2021 to May 31, 2022)10.4
Number of notifications sent (February 25, 2021 to May 31, 2022)456,359
Number of OTKs entered by users after notification (from April 1 to May 31, 2022)2,446

From April 1, 2021 to May 31, 2022 COVID Alert sent more than 448,000 notifications. For the same period, COVID Alert notifications have  helped identify at least 2,446 confirmed cases of COVID-19.

Of note, a recent studyFootnote 1 from researchers at Washington State University concluded that exposure notification tools represent an effective novel public health intervention to mitigate the spread of COVID-19. This conclusion is based on a study of the Washington Notify app (which is built on the same GAEN framework as Canada’s COVID Alert app) estimating that it prevented 5,500 COVID-19 cases and saved between 40 and 115 lives in the span of 3 months. The authors state that as new variants emerge and non-essential travel bans are lifted, exposure notification tools can continue to play a valuable role in limiting the spread of COVID-19. It is important to note that Washington State systematically provides an OTK by SMS to all positive cases, regardless of whether or not they have the app.

In a future public health crisis, digital services will need to leverage early and meaningful analytics to effectively communicate the benefits of the technology to all stakeholders. In this respect, COVID Alert is creating a blue-print for how digital tools will be integrated into public health.

Concluding observations and lessons learned

In the context of an unprecedented global pandemic, COVID Alert was developed to be a complimentary pan-Canadian tool to help alleviate the burden on local public health units and their contact tracers and support the fight against COVID-19. While the full impact of the app may only be evaluated retrospectively as lessons will continue to be gathered as this pandemic evolves, the Council has nonetheless identified early lessons and considerations that should be leveraged in the event of a future public health crisis.

  1. Privacy-first approach: The Government of Canada decided to design an exposure notification app rather than a contact tracing app to ensure a privacy-first model. The Council recognizes this approach has resulted in the limited ability to measure the impact of the app against public health outcomes. Despite this, the Council would still recommend a privacy-first approach for future apps. Given that Canadians view privacy as a quasi-constitutional right, the Council feels that offering such protections will be instrumental to promote app adoption by the Canadian public. Furthermore, in preparation for future public health events, the Council encourages the Government of Canada to clearly delineate the type of data that the government would require and be permitted to collect in a public health crisis, to place limits on its use and to clearly identify deletion requirements at the conclusion of the health emergency. This approach would consequently guide future digital response design and implementation alongside the timely deployment of metrics to measure its performance, while reassuring Canadians who place a high value on their privacy.

  2. Pan-Canadian approach: It is important to recognize that within the Canadian federation, each province and territory maintains a distinct identity and role in the provision of public health services to the population. Because of varying public health guidelines across the country, effective consultations were required to ensure the notifications were adaptable to all jurisdictions.

    The pan-Canadian approach used for the COVID Alert app provided an opportunity to evaluate the constraints of a national app that is interoperable across jurisdictions. It was also a platform to learn how to better federal-provincial-territorial working relationships. When compared to a provincial-territorial optional approach, the Council notes that the pan-Canadian approach still required buy-in from provinces and territories and therefore needed to resonate with PT leaders.

    Council recommends that the Government of Canada continue to engage with PTs during post pandemic and beyond to uphold relationships, solidify the consultation process and achieve concurrence on digital tool requirements and deployment principles. This cooperation will help to ensure optimal and rapid deployment of pan-Canadian digital tools to address future health crisis within all Canadian jurisdictions.

  3. OTK distribution process: OTK distribution and digital exposure notification systems were new for local public health systems. The Council believes that this notification feature was the biggest missed opportunity towards using COVID Alert more effectively in helping to slow the spread of infection. Scarcity and inconsistencies in the distribution of OTKs are one of the key reasons why COVID Alert did not reach its full potential. Of the total OTKs generated, approximately 69 percent were entered in the app (as of May 31, 2022).

    Council recommends that early consultations and agreement on processes required to support a future health crisis take place as part of the lessons learned. Gaining a better understanding with provinces and territories on how digital public health tools will be leveraged, with respective responsibilities delineated, will be critical towards ensuring a more effective response in future public health crisis.

  4. Communication and Marketing: A number of communication and marketing strategies were utilized by the Government of Canada and its provincial and territorial partners to promote the app. A diverse range of ambassadors, influencers, and community animators in marginalized communities and widespread marketing efforts were used in an unprecedented way to raise awareness of the app.

    Council recognizes that outreach is critical to app adoption rates and recommends that this approach be enhanced for future tools. An effective communication strategy driving the success of a digital service should focus on clear, accurate, accessible and positive messaging, in addition to adoption incentives to broaden uptake.

Conclusion of the Advisory Council

The Council was committed to providing advice and guidance to the Government of Canada to help ensure that the app meets the highest standards in public health outcomes, privacy, and technology.

Considering the adoption, retention, and use of COVID Alert as a government service and as a public health tool, the Council views the app as an important endeavour, despite it not having reached its full potential. The lessons from this pandemic regarding the use of digital tools in the public health sphere offer an important opportunity to plan ahead for what we know is not the last public health crisis.

COVID-19 Exposure Notification App Advisory Council


Jean-François Gagné, ServiceNow

Carole Piovesan, INQ Data Law


Simone Atungo, Vibrant Healthcare Alliance

Dr. Jonathan Dewar, First Nations Information Governance Centre

Dr. Bunmi Fatoye, Winnipeg Regional Health Authority

Dr. Éloïse Gratton, Borden Ladner Gervais

Andrew Harrison, Verily Life Sciences

Dr. Brenda McPhail, Canadian Civil Liberties Association

Dr. Derek Ruths, McGill University

Dr. Margo Seltzer, University of British Columbia