A cross-sectional study on vaccine coverage and seroprevalence in schoolchildren in Andorra.

A cross-sectional study on vaccine coverage and vaccine effectiveness was carried out on a randomized sample of the cohort of schoolchildren born in 1983 attending school in Andorra, prior to the introduction of a Systematic Immunisation Plan that included centralised import and delivery of vaccines to vaccinating clinics, surveillance of the cold-chain during vaccine delivery, and a clearly-defined immunization schedule against diphtheria, tetanus, -pertussis, polio, mumps, rubella and measles. Vaccine coverage was estimated from vaccination card records; history of disease and sociodemographic variables were obtained through a questionnaire to the children's parents and vaccine effectiveness was estimated through serum antibody testing. Vaccine coverage levels for DTP and OPV were 97.