Introduction

Public Health Ontario has released the latest estimates for immunization coverage and Immunization of School Pupils Act (ISPA)-antigen exemptions at the Health Unit level. The following is a brief summary of the key findings relevant to Windsor and Essex County (WEC).

Key Findings for WEC (2017/18 School Year)

Comparison to the province

1. Immunization coverage rates for children in WEC for ISPA-designated diseases were similar to or higher than Ontario
   
   1. ISPA designated diseases: measles; mumps; pertussis; polio; rubella; tetanus; diphtheria; meningococcal diseases; and varicella
2. Coverage rates for all except one non-ISPA designated disease were similar to or higher than Ontario
   
   1. Non-ISPA designated diseases that were assessed include: pneumococcal disease, haemophilus influenza type b; human papilloma virus; hepatitis B
   2. Coverage for Haemophilus influenza type b was 2.4% lower in WEC than Ontario (80.0% in WEC and 82.4% in Ontario).

Comparison to the national goal

3. Coverage estimates in 7-year olds only met the national goal of 95% for two diseases (meningococcal disease and rubella). There is no national goal for varicella.
4. Coverage estimates in 12-year olds for diseases covered by the school-based immunization program did not meet the national goal of 90%.
5. Coverage estimates in 17-year olds met the national goal for measles, mumps, and rubella. The national goal for measles, mumps, rubella and polio is 95%. The national goal for diphtheria, tetanus and pertussis is 90%

Change from the 2013/14 school year

Additional information from similar coverage reports published by Public Health Ontario covering the 2013/14 to 2016/17 school years were collated to present the trends over time for immunization coverage.

7-year olds

6. Coverage in 7-year olds for ISPA-designated diseases has improved from 2013/14. The percentage point difference varies by disease and ranges from:
   
   1. less than a 1.0% increase in coverage for measles, mumps and rubella;
   2. 10.1% to 13.2% increase for pertussis polio, tetanus, diphtheria, and meningococcal disease; and
   3. 53.6% increase for varicella
7. Coverage in 7-year olds for non-ISPA designated diseases has declined:
   
   1. 4.9% decrease in coverage for pneumococcal disease. Coverage has decreased year-to-year for three of the last four school years.
   2. 5.0% decrease in coverage for haemophilus influenza type b

12-year olds

8. Coverage in 12-year olds for meningococcal disease has increased by 3.1%
9. Coverage in 12-year olds for non-ISPA designated diseases have varied:
   
   1. 2.1% decrease for hepatitis B
   2. 1.0% decrease for HPV
   3. The lower coverage estimates for these diseases may be due to their non-ISPA designation. The health unit does not actively collect immunization records for these diseases.

17-year olds

10. Coverage in 17-year olds for ISPA-designated diseases has varied:
    
    1. 1.3% and 2.1% increase for measles and mumps, respectively
    2. 0.3% and 0.5% decrease for polio and rubella, respectively
    3. 36.2% to 37.3% increase for diphtheria, pertussis, and tetanus

Exemptions for at least one ISPA antigen

11. The proportion of students with medical and non-medical exemptions was relatively low.  Only 0.3% of 7-year olds and 0.2% of 17-year olds had a medical exemption for at least one ISPA antigen.  These proportions were similar to that of Ontario.
12. The proportion of students with a non-medical exemption was slightly higher. 3.4% of 7-year olds and 2.6% of 17-year olds had a non-medical exemption for at least one ISPA antigen. The proportion of 7-year olds with a non-medical exemption was slightly higher than Ontario (0.6% higher).