Immunization completeness of children under two years of age in Nova Scotia, Canada

Objectives: Canada's progress in establishing a national immunization registry and coordinated immunization schedule across provinces has been slow. The absence of a centralized registry means there are only limited data available on childhood immunization coverage in Canada. The aim of this study was to estimate the completeness and timeliness of immunization for two year-old children in Nova Scotia. Methods: The study included 8,245 babies born in Nova Scotia during 2006. Immunization data were derived from three sources: Provincial Medical Insurance Physician Billing data, public health records, and self-report by parents. Immunization uptake rates for vaccines included in the Nova Scotia immunization schedule were calculated at ages 12, 18 and 24 months. Logistic regression was used to analyze vaccine uptake in relation to socioeconomic factors. A telephone survey of a sample of parents of study children was completed. Results: The overall immunization completeness rate was 49% at 12 months, 40% at 18 months and 58% at 24 months of age. Immunization completeness was significantly higher in more socially disadvantaged communities. Conclusions: Nova Scotia spends many millions of dollars on vaccine purchase and administration, but, as with numerous Canadian jurisdictions, there is no accurate system for monitoring or evaluating the program. The timeliness and completeness of immunization administration to pre-school children in Nova Scotia is inadequate. Further work should elucidate the barriers and enablers to immunization to ensure that public health education targets those most likely to be under-immunized. A provincial vaccination database should be established to monitor and evaluate the system.