Factors determining vaccine uptake in Western Australian adolescents

Aim: Adolescence is the final opportunity for a large-scale immunisation programme before adulthood. The Western Australian (WA) school-based vaccination programme provides Year 7 students with free vaccination against hepatitis B virus (HBV); diphtheria, tetanus and pertussis (dTpa); varicella zoster virus (VZV); and human papilloma virus (HPV). We aimed to identify factors determining consent form return and vaccination uptake. Methods: Data were collected via a statewide, web-based database in 2009 and 2010. Proportions of students who returned a vaccine consent form, and completed HBV and HPV multi-dose courses and dTpa and VZV vaccination were determined. Factors associated with these outcomes were identified with multivariate analysis using logistic regression, accounting for clustering by school. Results: In 2010, 92.8% of WA Year 7 students returned a vaccination consent form and 85.3%, 74.3%, 66.7.0% and 26.4% completed their adolescent vaccination(s) against dTpa, HPV (females only), HBV and VZV, respectively. Consent form return and dTpa vaccination uptake improved between 2009 and 2010. Independent and consistently negative associations were observed between outcome variables (consent form return and vaccine uptake) and male gender, geographically remote schools, government schools and schools in the most socio-economically disadvantaged areas. Both HBV and HPV course completion were higher in Catholic than government schools, and the same in government and independent schools. Conclusion: To effectively maximise vaccination coverage, the WA school-based adolescent vaccination programme must specifically target male students and schools in the most disadvantaged and remote areas.