Measles Elimination in Canada Measles is a severe respiratory tract infection frequently complicated by pneumonia, croup, sinusitis, otitis media, and febrile convulsions. It is the most contagious infection of humans. Every year, nearly one million children die from it worldwide.
Available vaccines are safe and effective.
Before immunization, an estimated 300,000 to 400,000 cases of measles occurred annually in Canada. The spread of the virus was likely caused by the small proportion of children who failed to respond to primary vaccination or, less commonly, by those who lost protection over time after vaccination. It was increasingly clear that a routine one-dose program administered after 12 months of age would not achieve the goal of eliminating indigenous measles because of its extreme contagiosity. This was strongly supported by the international experience. Control measures such as exclusion from school and emergency mass revaccination are extremely disruptive, costly, and of limited effectiveness.