Vaccination coverage and factors associated with incomplete polio vaccine schedule in children born in 2017-2018, in state capitals and interior region municipalities of Northeast Brazil

Cobertura vacunal y factores asociados al esquema incompleto de vacunación contra la polio en nacidos en capitales y municipios del interior del Nordeste de Brasil entre 2017 y 2018

Objective  To analyse vaccination coverage and factors associated with incomplete polio vaccination in a cohort of children born in 2017-2018, in state capitals and interior region municipalities of Northeast Brazil.

Methods  Household survey of children aged ≤24 months conducted between 2020 and 2022. Vaccination coverage and dropout rates were estimated, as well as factors associated with incomplete vaccination, analyzed by calculating odds ratios (OR) and 95% confidence intervals (95%CI).

Results  : Among 12,137 children, vaccination coverage (4 doses) was 80.9% (95%CI 78.4;83.1); 8.4% were not vaccinated. Not having a vaccination card (OR=18.06; 95%CI 10.01;32.61) and use of private services (OR=1.46; 95%CI 1.23;1.74) were associated with incomplete vaccination. Higher dropout rates were found for the booster dose, especially in the highest stratum.

Conclusion  Low vaccination coverage, poor dose follow-up and high dropout rates were found for polio vaccines in the areas studied.

Keywords
Vaccination Coverage; Poliovirus Vaccines; Poliomyelitis; Health Surveys

Main results  80.9% poliomyelitis vaccination coverage, with non-vaccination associated with both better and poorer sociodemographic conditions, in addition to use of private health services, having more than one child per mother and not having a vaccination card.

Implications for services  High risk of poliomyelitis reemerging highlights the need to expand access to healthcare, with greater reinforcement of effective vaccination strategies. Actions must prioritize primary care in different territorial realities in Northeast Brazil.

Perspectives  The evidence generated provides additional support for decision-making in the Brazilian National Health System based on microplanning, aiming to overcome critical barriers to access to health services, and thus achieve poliomyelitis vaccine coverage targets.