27: School-Based Vaccination Programs in ontario: Vaccine Coverage and Non-Medical Exemptions

Abstract

Background: Ontario uses school-based vaccination delivery for three adolescent programs: hepatitis B (HB) (since 1994/5), meningococcal conjugate (serogroup C from 2005/6, serogroups A,C,Y,W-135 since 2009/10), and human papillomavirus (HPV) (since 2007/8). HB (two doses) and quadrivalent meningococcal (one dose) vaccination is offered to grade 7 students and HPV vaccine (three doses) to grade 8 girls. Until 2012/13, all 36 Public Health Units (PHUs) assessed vaccine coverage and recorded immunization exemptions using the Immunization Records Information System (IRIS). Under Ontario legislation, for six designated diseases (measles, mumps, rubella, diphtheria, tetanus and polio), students with incomplete immunizations must be vaccinated or provide a statement of exemption, otherwise risk school suspension. Objectives: 1) To present coverage for Ontario's three school-based vaccination programs for the 2012/13 school year, and to relate these to recent temporal trends and national coverage targets; 2) To describe temporal trends in immunization exemptions to measles-containing vaccines (MCV) among Ontario students between 2002/3 and 2012/13. Design/Methods: In June 2013, IRIS immunization coverage data were requested from all PHUs for select publicly-funded vaccine antigens. Data reflected immunizations delivered as of June 30, 2013. PHU-specific data were compiled to derive provincial estimates following a validation step. Historical data from IRIS were reviewed to present historical trends in coverage and information on MCV exemptions. Trends in exemptions were expressed for sevenand 17-year-olds by classification (medical, religious/conscientious belief, total) at a provincial and regional level, and by school year and birth cohort. Poisson distribution was used to examine temporal trends. Results: Coverage and exemptions data for 2012/13 will be presented but are currently being validated. Ontario coverage for the 2011/12 school year was 86.6% for HB, 84.4% for the meningococcal program, and 70.2% for HPV, representing notable increases in coverage for HPV (11.8%) and HB (10.0%), as compared to the 2010/11 school year. For both seven- and 17-year-old students, religious/conscientious exemptions for measles-containing vaccines significantly increased over the period of study (both P<0.001). However, the proportion of Ontario students with any exemption classification (total exemptions) remained low (<2%) and relatively stable over the period of analysis. Considerable geographic variation in coverage and exemptions was noted. Conclusions: School-based delivery of adolescent vaccination programs is an effective strategy for achieving high provincial coverage. Ontario data suggest that non-medical exemptions have increased over the last ten years, consistent with trends found elsewhere, although the proportion remains low at <2%.