Canada’s COVID-19 Response: Analyzing the Complexity of Public Health Interventions

Looking for an example of a complex adaptive system? Just consider the public health response to COVID-19 over the past year. In this post, Ameera Kanjee considers what we learn about systems by reflecting on Canada's pandemic strategy.

by Ameera Kanjee (CAS Lab, Practicum Placement, Fall 2020 and Winter 2021)

Over the past year, the COVID-19 pandemic has transformed every aspect of our lives and daily routines. By March of 2020, active COVID-19 cases were increasing, and virus transmission had become an imminent public health concern. Health officials began implementing a series of measures that would fundamentally change how Canadians live. Lockdowns and calls for physical distancing led to companies shifting to work from home, implementation of travel restrictions, mandated masks, and cancellation of major events. It also resulted in an exponential increase in video conferencing, as people were asked to stay home and avoid all in-person interactions. As the pandemic evolves, public health terms are becoming common household phrases: flattening the curve, physical distancing, contact tracing, and herd immunity.

As new policies and public health guidelines constantly emerge, I recognize the complexity represented within Canada’s COVID-19 response, and the way in which public health interventions embody a Complex Adaptive System (CAS). Public health challenges are rooted in the five social domains (education, family, religion, workplace, and government), reinforcing the importance of applying a multidisciplinary approach in order to improve community health. We typically apply linear models of cause and effect to explain health outcomes. However, it is critical to harness evidence-based solutions and apply a systems thinking lens when forming policies that target the root cause of health disparities. Public health challenges that emerge as a complex system can’t be solved with a single intervention. Many interacting factors are required to generate desirable outcomes. Common features of complex adaptive systems are represented within public health challenges and strategies. Emergence exemplifies individual components that interact in a wider context. For example, chronic disease is an emergent property of lifestyle habits, genetics, race, social class, eating patterns and physical activity. Adaptation is another key concept related to complexity theory, referring to adjustments in behaviour in response to public health interventions.

Interdisciplinarity of Public Health Interventions

Canada’s response to COVID-19 led to policy changes and the implementation of public health guidelines that demonstrate the challenges of intervening within a complex system. Strategies were enforced to reduce transmission of the virus and prioritize public safety. Many stakeholders were involved in developing these public health mandates, including government officials, public health specialists, and infectious disease clinicians. These individuals have a common interest in improving community health and greatly influence decision outcomes. Engaging a variety of stakeholders and applying an interdisciplinary lens results in developments within various social domains, including the economy and education sector. This multifaceted approach is crucial in creating public health interventions and addressing the root causes that accelerate the severity of health challenges.

Differences in Morbidity and Mortality Related to COVID-19

The social and personal determinants of health represent a complex adaptive system. Many external factors such as income, housing, and access to adequate nutrition, contribute to shaping an individual’s overall health outcomes and experiences. Health inequities arise from unequal access to social and personal determinants of health. The conditions in which people live and work lead to differences in exposure, susceptibility and treatment of COVID-19. These factors result in disparities with respect to morbidity and mortality rates for varying demographic groups. 

  1. Differential exposure: Occupational factors, such as the ability to work from home, paid sick leave, job security, and childcare, influence an individual’s exposure to the virus. Being positioned in essential services on the front lines leads to a heightened risk of contracting COVID-19, due to increased in-person interactions. In addition, living conditions such as neighbourhood characteristics and crowded housing, impact an individual’s level of exposure to infectious disease particles.
  2. Differential susceptibility: Various biological factors increase an individual’s susceptibility to becoming ill. Older adults and people with underlying health conditions are more susceptible to infection, because they have impaired immune function and an increased prevalence of comorbidities. In addition, health behaviours such as nutrition habits, levels of physical activity, and substance use, act as risk factors that increase an individual’s susceptibility of experiencing negative health outcomes.
  3. Differential treatment: Various financial and logistical barriers, such as transportation and language, impact an individual’s access to healthcare services. Inequalities rooted in systemic racism, discrimination and preconceived biases influence the quality of healthcare received by people who belong to racial and ethnic minority groups. These societal factors lead to differences in accessibility and affordability of healthcare, resulting in negative health impacts and an increased incidence of disease.

Differences in morbidity and mortality related to COVID-19 are strongly rooted in the social and personal determinants of health, resulting in varied health outcomes. Health inequities are exacerbated amongst individuals of lower socioeconomic status, and people who belong to minority populations. These individuals experience more adverse implications related to COVID-19 and have an increased risk of morbidity and mortality.

Complexity Within Canada’s COVID-19 Response

Public health measures implemented to limit the spread of COVID-19, such as quarantine and physical distancing, have had immediate negative impacts on the health and wellbeing of many individuals. Periodically over the past year, hundreds of thousands of Canadians have experienced unemployment due to economic closures and have relied on government subsidies to support their families. Rates of domestic violence and substance-related harm have increased due to lockdowns and the inability to escape toxic environments. Public health measures have negatively impacted social cohesion and connectedness, resulting in feelings of loneliness and isolation, thus contributing to poorer wellbeing and mental health of Canadians. Declines in physical activity and food insecurity are common and put individuals at an increased risk of experiencing negative health outcomes. Many individuals experience stigma and discrimination rooted in racism, classism and ageism. Different demographic groups within Canada’s diverse population are disproportionately impacted by public health interventions, resulting in an increased need for support. Canada’s COVID-19 response is built on a strong framework that applies a multifaceted approach and accounts for the various needs of different population groups:

  • Support to provinces and territories: In order to ensure equitable support across the country, the Canadian government has invested more than $19 billion in funding to provinces and territories. The intent of this funding is to assist with investments in priority areas such as: increasing testing and contact tracing, strengthening support for healthcare systems, securing personal protective equipment (PPE), and supporting those at risk of severe illness from COVID-19. In addition, Canada’s National Emergency Strategic Stockpile has been buying PPE, testing supplies, and medical equipment (such as ventilators) in bulk, in order to contain the outbreak and prevent further spread.
  • Economic and financial support: The Government of Canada is taking significant action to support Canadians and businesses facing challenges as a result of the COVID-19 pandemic. The government has a number of financial support programs for individuals experiencing unemployment. Financial support also exists for businesses, allowing them to avoid layoffs, rehire employees and create new jobs. Individualized support exists for Canadians who are self-employed and for Indigenous businesses, as well as for businesses within specific sectors, such as agriculture, aquaculture, energy and infrastructure.
  • Border measures and travel: Canadians have been advised to limit all non-essential travel outside of Canada, and strategies have been employed to limit international spread of COVID-19 caused by travel. Canada has restricted all international passenger flight arrivals to four major airports in the country: Calgary, Toronto, Montreal and Vancouver. The Public Health Agency of Canada has also positioned clinical screening officers at key high-volume ports of entry across Canada.
  • Digital tools and apps: Canada has developed tools, such as the COVID Alert app which notifies individuals if someone they were in close contact with in the past 14 days records a positive test result.
  • Public education: Canada has created resources that are timely, accessible and evidence-informed in order to increase awareness and understanding of the disease, explain prevention strategies and address misinformation. These resources are available on many platforms and in many languages, and cover topics such as handwashing, mask wearing and isolation practices.
  • Research and technology: Canadian researchers are working to support international efforts and advance technological developments. Research is taking place to enhance Canada’s capacity to develop vaccines, support clinical trials and test antiviral treatments.

This multifaceted approach is a by-product of a democratic system that distributes power between various levels of government. This is a significant contributing factor that influences the implementation of policies and impacts our ability to respond to COVID-19. For example, mandatory mask policies have been implemented periodically over the past year by provincial governments, whereas travel restrictions were enforced by the federal government.

Public health interventions have direct and indirect impacts, reinforcing the importance of approaching health crises from a complexity lens. This allows us to predict cause and effect outcomes that stem from the health issue and employ adequate methods of solving diverse problems. Canada’s COVID-19 response represents a holistic approach that encompasses various strategies to target specific social domains.

Moving Forward from the COVID-19 Pandemic

Canada’s COVID-19 response resulted in several structural changes that were employed to preserve the health of communities and reduce virus transmission. Moving forward, many of these changes will be integrated into society as we develop an increased awareness of disease and accommodate for evolving public health measures. These transitions exemplify a systems thinking approach, and are rooted in diverse social domains. Some developments may include:

  • Reconfiguration of long-term care facilities, prisons, university residences, homeless shelters and other congregate living settings to accommodate for physical distancing and reduce the risk and susceptibility of infectious disease transmission
  • Organizations permanently transitioning to a work from home model as businesses plan long-term changes to office structure and resource allocation
  • Increased concern for environmental sustainability due to a surge in use of disposable masks, gloves, antibacterial cloths, and single-use plastics
  • Changes in infrastructure to accommodate for the emphasis on hygiene practices, such as handwashing
  • Modifications to retail businesses to support contactless payment, online ordering, and delivery
  • Advancements within healthcare delivery, such as telemedicine, to reduce health disparities and barriers rooted within the social determinants of health
  • Modifications to the airline industry due to changes in commercial air traffic and varying methods of travel

As we look ahead towards recovery from the pandemic, increased intersectoral collaboration will improve cohesion and connectedness amongst social domains in Canada. Although Canada’s COVID-19 response has proven that our country is extremely resilient and adaptable, we must shift our focus to areas of high impact, such as: economic stability, employment conditions, housing environments, healthcare delivery, education systems, and environmental sustainability. Leveraging complexity within public health interventions and reinforcing intersectoral collaboration will enable Canada to be better equipped to respond to future health crises.

Canada’s immunization response exemplifies a complex adaptive system through collaboration between government officials, public health experts, scientists, and clinicians. The immunization response is large and multifaceted, requiring a strong framework and a systems thinking approach to achieve successful vaccine distribution. Moving forward, our ability to leverage interdisciplinarity and apply a complexity lens to the implementation of public health interventions must be considered in order to create a more sustainable, resilient and equitable future.


Government of Canada. (2021). Coronavirus disease (COVID-19): Canada’s response.

Additional Resources

Government of Canada. (2020). Social determinants of health and health inequalities.

Healthline. (2020). What’s the difference between morbidity and mortality?

De Domenico, D. Brockmann, C. Camargo, C. Gershenson, D. Goldsmith, S. Jeschonnek, L. Kay, S. Nichele, J.R. Nicolás, T. Schmickl, M. Stella, J. Brandoff, A.J. Martínez Salinas, H. Sayama. Complexity Explained (2019). DOI 10.17605/OSF.IO/TQGNW

World Health Organization. (n.d). Social determinants of health.