The study aimed to evaluate vaccination coverage and factors associated with incomplete basic vaccination schedule at 12 months of age in 427 children aged 12-59 months in São Luis, Maranhão State, Brazil, 2006. This cross-sectional, population-based household survey used complex cluster sampling. Poisson regression with robust adjustment of variance was applied. Complete basic vaccination coverage was 71.9% for applied doses, 61.8% for valid doses, and 23.6% for correct doses. Hepatitis B and tetravalent vaccines showed higher percentages of doses on dates or at intervals lower than recommended. Percentages of delayed vaccination were high, except for BCG. Incomplete basic vaccination was more frequent in girls and children from low-income and black families. Racial, gender, and socioeconomic factors posed barriers to complete vaccination, thus emphasizing the need for policies to address such inequalities.
Immunization; immunization Coverage; Child Health
