Human papillomavirus (HPV) vaccination coverage in Brazil: spatial and age cohort heterogeneity

ABSTRACT:

Objective:

To estimate the coverage of the first and second dose of the human papillomavirus (HPV) vaccine in Brazil according to microregion, comparing cohorts of girls aged 14, 15, and 16 years in 2017, and investigate the association between spatial heterogeneity in vaccination coverage and sociodemographic variables.

Methods:

Information about the doses administered from 2013 to 2017 by age was gathered from the National Immunization Program. The number of girls aged seven, eight, and nine years living in each microregion in 2010 was obtained from the 2010 Brazilian Census. For the analysis, the cumulated vaccination coverage per microregion (n = 558) was categorized as low (< 80%) and adequate (≥ 80%), and a random intercept logistic model was adjusted, with adequate vaccination coverage as the outcome. The random effect (federative unit) was included to identify the correlation between microregions that belong to the same state.

Results:

The percentage of microregions with adequate vaccination coverage was significantly higher in the first dose (between 91.8 and 159.2%), regardless of the cohort. The coverage of the second dose was lower (between 7 and 79.9%), with heterogeneity associated with the degree of urbanization and households with private bathrooms in the municipality. The random effect showed a strong explanatory power, suggesting important differences among Brazilian states as to the outreach of vaccination coverage.

Conclusion:

Although the HPV vaccine is available through the Immunization Program, the findings of the present study point to a difficulty in achieving adequate vaccination coverage.

Keywords:
Immunization; Vaccination coverage; Papillomaviridae; Ecological studies