Vaccination coverage among children under two years of age based on electronic immunization registry in Southern Brazil

Abstract

OBJECTIVE: To evaluate the immunization program for 12 and 24-month-old children based on electronic immunization registry. METHODS: A descriptive study of a random sample of 2,637 children born in 2002 living in the city of Curitiba, Southern Brazil was performed. Data was collected from local electronic immunization registers and the National Live Birth Information System, as well as from a household survey for cases with incomplete records. Coverage at 12 and 24 months was estimated and analyzed according to the socioeconomic characteristics of each administrative district and the child's enrollment status in the health care service. The coverage, completeness, and record duplication in the registry were analyzed. RESULTS: Coverage of immunization was 95.3% at 12 months, with no disparities among administrative districts, and 90.3% at 24 months, with higher coverage in a district with lower socioeconomic conditions (p < 0.01). The proportion of vaccines, according to type, given before and after the recommended age reached 0.9% and 32.2%, respectively. In the surveyed sample, electronic immunization registry coverage was 98%, underreporting of vaccine doses was 11%, and record duplication was 20.6%. Groups with highest coverage included children with permanent records, children with three or more appointments through the National Unified Health Care System, and children seen within Primary Health Care Facilities fully adopting the Family Health Strategy. CONCLUSIONS: Vaccination coverage in Curitiba was high and homogeneous among districts, and health service enrollment status was an important factor in these results. The electronic immunization registry was a useful tool for monitoring vaccine coverage; however, it will be important to determine cost-effectiveness prior to wide-scale adoption by the National Immunization Program.