Vaccine coverage during a school-based hepatitis B immunization program.

Ontario initiated a universal hepatitis B immunization program for grade seven students in the fall of 1994. An ecological study was conducted within seven health units of the Greater Toronto Area to assess vaccine coverage. The study population consisted of all grade seven students enrolled within schools in the participating health units, on October 1, 1994. There were 39,935 students enrolled in 604 schools eligible for inclusion in the study. Consent to receive the vaccine series was obtained for 88% (range across health units from 81.5% to 96.3%) of the students. Among students for whom consent was obtained, an average of 95% (range 88.1% to 99.5%) completed the series. Therefore, the total vaccine coverage for the study population was 84% (range 77.5% to 89.5%). Series completion varied by school board, education provider and the use of Ministry of Health educational material. A limiting factor in achieving high vaccination coverage among grade seven students was obtaining consent to receive the vaccine series.