RÉSUMÉ
BACKGROUND: The aim was to verify the prevalence of vaccination coverage, tendency and factors of the third dose of the vaccine against diphtheria, tetanus and pertussis-DTP3 in surveys over the period of 25 years in a state of the Northeast of Brazil. METHODS: Cross-sectional and temporal series, utilizing ad hoc database, were extracted from the Health and Nutrition State Research 1991, 1997, 2006 and 2015/2016. Children from 12 to 23 months of age with proof in the vaccination card were included. The vaccination coverage (outcome) of each year was calculated, the tendency throughout the period was analyzed and the associations through Pearson chi-squared were tested. The results of the first and last survey were compared with a significance level of 5%. The reasons of the crude prevalence and confidence intervals of 95% were estimated. RESULTS: The vaccination coverage in 1991, 1997, 2006 and 2015/2016 was 77.6%, 82.7%, 89.7% and 72.9%, respectively, with an increasing tendency from 1991 to 2006 (p<0.001) and decreasing between 2006 and 2015/2016 (p<0.001). Factors in 1991: low socioeconomic conditions; lack of access to health service and pre-natal care, nutritional deficit and diarrhea in children (p<0.005). In 2015/2016, low socioeconomic conditions and diarrhea persisted and a larger family size, black, negative self-perception of happiness, both from the mother (p<0.05), were identified. CONCLUSION: The factors of the recent decrease of vaccination coverage are complex, multifactorial, dependent of context and even on subjective aspects of the maternal perception. Its identification contributed to the understanding of inadequate vaccination at the state level.
RÉSUMÉ
BACKGROUND: Globally, childhood immunization saves the lives of 2-3 million children annually by protecting them against vaccine-preventable diseases. In 2017, 116.2 million children were vaccinated worldwide according to the World Health Organization. Nevertheless, figures suggest that 19.5 million children around the world fail to receive the benefits of complete immunization. METHODS: This cross-sectional study analyzed vaccine uptake and the factors associated with incomplete vaccination schedule in children of up to 36 months of age assisted by the family health strategy in an irregular settlement located in a state capital city in northeastern Brazil. This study was nested within a larger study entitled "Health, nutrition and healthcare services in an urban slum population in Recife, Pernambuco", conducted in 2015. A census included 309 children, with vaccination data obtained, exclusively, from their vaccination cards records. An ad hoc database was constructed with variables of interest. Absolute and relative values were calculated for the socioeconomic, demographic, obstetric and biological data. To identify possible factors associated with incomplete vaccination schedule, crude and multivariable Poisson regression analyses were performed, and conducted in accordance with the forward selection method with robust variance and the adjusted prevalence ratio was calculated with the 95% CI. Variables with p-values < 0.20 in the unadjusted stage were included in the multivariable analysis. The statistical significance of each variable was evaluated using the Wald test, with p-values < 0.05. RESULTS: Just half of the children (52,1%) was classified as complete vaccination schedule. In the final model, the factors associated with incomplete vaccination schedule were age 12-36 months and the mother who did not complete high school. CONCLUSION: The percentage of vaccine uptake found was far below the recommendation of the National Childhood Immunization Schedule and was associated with child's age and mother's education level. Based on these findings, the family healthcare teams may elaborate vaccination strategies aimed at reaching the coverage rates established by the national immunization program. Optimizing coverage will ultimately prevent the resurgence, at epidemic level, of infectious diseases that are already under control in this country.