Borders and Blood Fractions: Gamma Globulin and Canada's Fight against Polio, 1950-55.

During the early 1950s, Canada's efforts to prevent polio became heavily influenced by developments in the United States. America's foremost polio charity, the National Foundation for Infantile Paralysis, sponsored University of Pittsburgh researcher Dr. William McD. Hammon to evaluate the efficacy of a human blood fraction, gamma globulin (GG), to prevent paralytic polio. When the resulting clinical trial data appeared to show that the blood fraction offered some protection against the disease, Canadians embraced the concept for reasons of historical trust, parental demand, and public health pragmatism. They established Canada's first national immunization program to fight polio before the vaccine, as well as developed a plan to produce, evaluate, and distribute GG to epidemic areas. Despite being an expensive enterprise for a geographically vast and sparsely populated nation, Canada's GG program was extended to citizens and it became an important response to polio before a safe and effective vaccine was licensed. Although the blood fraction was not as effective at preventing polio paralysis as researchers had anticipated, its systematic use reveals how Canadian health leaders drew on transnational relationships to reduce the incidence of disease.