Dr. Vaillancourt obtained his doctorate in veterinary medicine (1983) and his master of science in clinical sciences (1986) from the University of Montreal and his doctorate in population medicine from the University of Minnesota (1990).
Before returning to the University of Montreal, he held professorships at the University of Guelph in Ontario (1990-1996), at North Carolina State University in Raleigh (1996-2004) and was a visiting professor at the National Autonomous University of Mexico in Mexico City (2002-2003). He was also a visiting professor at the National School of Veterinary Medicine in Toulouse, France (2017-2018).
Dr. Vaillancourt acted as the first coordinator of the Quebec team for the control of poultry diseases for the design and implementation of emergency measures. He was chief auditor of avian influenza and foot-and-mouth disease simulations in Ontario, Quebec, New Brunswick, and France. He has been a member of Canadian advisory committees for the control of infectious diseases in poultry, swine and beef cattle. He has served as an expert in animal health and welfare for the National Agency for Food, Environmental and Occupational Health and Safety (France), in particular on on the emergency committees for avian flu and African swine fever.