Inquérito nacional de cobertura vacinal infantil e Programa Nacional De Imunização na capital do Maranhão: uma análise comparativa

Abstract

Childhood vaccination coverage is one of the main indicators of health system performance, as it reflects the capacity to prevent vaccine-preventable diseases and reduce child morbidity and mortality. In Brazil, these actions are organized through the National Immunization Program (PNI), historically recognized for its advances in universal access to vaccines. In recent decades, the country has faced declines in vaccination coverage, increased dropout rates in multidose schedules, persistent socioeconomic inequalities, and weaknesses in health information systems, which compromise the monitoring and effectiveness of immunization actions. This study aimed to compare vaccination coverage indicators and dropout rates obtained through the National Vaccination Coverage Survey (INCV) with those recorded in the National Immunization Program Information System (SI-PNI), in the municipality of São Luís, Maranhão, among children under one year of age born in 2017 and 2018. This is a descriptive study based on INCV data collected between 2020 and 2022, and administrative records from the SI-PNI referring to the years 2017 and 2018. The sample consisted of 854 children living in the urban area of São Luís, distributed across four socioeconomic strata (A, B, C, and D). Vaccination coverage for immunobiologicals included in the first-year childhood immunization schedule was analyzed, as well as dropout rates for vaccines requiring multiple doses. The results showed differences between vaccination coverage estimated by the INCV and recorded in the SI-PNI, respectively: meningococcal C (2nd dose), 92.0% and 71.4%; pentavalent (3rd dose), 91.9% and 70.1%; poliomyelitis (3rd dose), 91.9% and 70.0%; pneumococcal (1st booster), 90.8% and 65.5%; meningococcal C (1st booster), 89.3% and 60.7%. The lowest coverage rates were observed in later booster doses, such as DTP (1st booster): 65.0% in the INCV and 53.1% in the SI-PNI. Dropout rates were higher for vaccines requiring multiple doses, with reduced adherence between the first and subsequent doses. In the SI-PNI, dropout rates were consistently higher than those observed in the INCV: pentavalent vaccine, 4.1% (INCV) and 18.5% (SI-PNI);

poliomyelitis, 2.0% (INCV) and 18.2% (SI-PNI); rotavirus, 8.6% (INCV) and 22.0% (SI- PNI); meningococcal C vaccine, 1.8% (INCV) and 8.3% (SI-PNI); and pneumococcal

vaccine, 0.7% (INCV) and 10.8% (SI-PNI). It is concluded that vaccination coverage and dropout rate indicators for children under one year of age born in 2017/2018 in São Luís, Maranhão, differed between the INCV and the SI-PNI, highlighting discrepancies between data sources and suggesting a possible underestimation of vaccination coverage and overestimation of dropout rates in administrative records.