Number cruncher: Using math to fight infectious diseases

Photo courtesy of Jonathan Robert,
Direction artistique Safran Design

CIHR Foundation Grant Recipient

Dr. Marc Brisson
Department of Social and Preventive Medicine
Faculty of Medicine
Laval University, Québec

Dr. Brisson's Research

To control and prevent infectious diseases, governments, at all levels, depend on scientific evidence to make informed decisions.

To address this need, Dr. Marc Brisson, a CIHR funded researcher, is building on his background in actuarial science, statistics, economics, and epidemiology, to develop state-of-the-art mathematical models that provide the information needed to better control infectious diseases and minimize the associated human and economic costs.

Public health decision-makers must make choices about vaccination (e.g., whether to introduce a new vaccine, who should be vaccinated, number of vaccine doses). Since new vaccines are often expensive, decision-makers require information on their anticipated costs and health benefits, in order to assess their value and cost-effectiveness. Source: World Health Organization

Transmission dynamics: Communicable diseases are transmissible by nature. The dynamics of an infectious disease is dependent on the transmission rate from an infectious individual to a susceptible individual.

From his laboratory at Laval University, Dr. Brisson studies not only the natural history and “transmission dynamics” of infectious disease, but also considers how intervention strategies can affect different socio-economic populations.

Dr. Brisson’s work has informed vaccination strategies worldwide. He has conducted extensive research on the incremental impact and cost-effectiveness of vaccination programs, and has helped inform vaccination policy decisions at the global level (mainly for chickenpox, shingles and human papillomavirus (HPV) vaccines.)

Predicting the population-level impact of vaccination programs is particularly challenging since vaccination not only prevents disease in those immunized but also indirectly protects individuals who are not vaccinated through herd immunity. Herd immunity has played a key role in the success of previous vaccines against infectious diseases (e.g., the eradication of smallpox.) Yet, the majority of the economic evaluations of vaccination programs use models that do not take into account the indirect effects produced by herd-immunity.

Dr. Brisson and his team are working hard to change that. A key focus of his work has been to include herd-immunity in cost-effectiveness analysis of vaccines.

Supporting advances in mathematical modelling to inform infectious disease prevention strategies

Recognizing the value of mathematical modeling and health economics as useful tools for evaluating and optimizing infectious disease prevention strategies, Dr. Brisson has assembled a multi-disciplinary team, including epidemiologists, mathematicians, statisticians, and engineers, focused on developing models to help prevent and control sexually transmitted infections, such as human papillomavirus (HPV) and human immunodeficiency virus (HIV). He is also studying Clostridium difficile (C. difficile), one of the most frequent causes of infectious diarrhea in hospitals and long-term care facilities in Canada.

The mathematical models being developed incorporate data on how diseases spread, and how different interventions work, like vaccination and screening. The models will help future decision making and demonstrate the potential of big data to address complex health challenges.

"Mathematical models have proven useful in these situations, as they provide a formal framework to integrate data from various sources, like clinical trials, and epidemiological studies, to make predictions about effectiveness and cost-effectiveness of health interventions for many different what-if scenarios."

Dr. Marc Brisson

Sought-after for his expertise, Dr. Brisson is a recognized leader who has consulted for the World Health Organization, the Centers for Disease Control and Prevention, the Public Health Agency of Canada, and the Canadian Immunization Committee.

In addition, he has published more than 75 peer reviewed journal articles, and has made over 100 presentations at international conferences, external seminars and workshops. He also leads the Modeling & Health Economics Research Network within the CIHR-funded Canadian Immunization Research Network.

About Dr. Brisson

A full Professor in the Department of Social and Preventive Medicine at Laval University, Dr. Brisson has a BSc in Actuarial Science, and an MSc in Epidemiology from Laval University, and a PhD in Health Economics from City University in London, England. He holds a Canada Research Chair in Mathematical Modeling and Health Economics of Infectious Diseases.

Date modified: