Social equity in Human Papillomavirus vaccination: a natural experiment in Calgary Canada

Background The Alberta Immunization Program offers a vaccine against the Human Papillomavirus (HPV) free of charge to all girls in Grades 5 and 9. The vaccine is provided in two different service delivery models depending upon the acceptance of the program by the local school board. Vaccinations may be provided “in-school” or in “community” through appointments at Public Health Clinics. The purpose of this study was to determine whether there was a difference in vaccine uptake in Calgary between the two service delivery models, “in-school” and “community”, and to examine if socioeconomic status (SES) was a contributing factor.