What is the impact of the safety signal on dengue vaccination coverage among adolescents in Brazil?

INTRODUCTION

The identification of safety signals, such as anaphylaxis linked to the dengue vaccine in adolescents in Brazil, can undermine public trust and necessitate adjustments to vaccination strategies, such as for the strategy restricted to health units. This study compared the vaccination coverage of dengue and HPV vaccines, both targeting the same age group.

METHODS

An ecological study based on secondary data from Brazilian Ministry of Health health information systems (administrative vaccination records) was conducted to analyze differences in dengue and HPV vaccination coverage among adolescents (10 to 14 years old) in municipalities prioritized for dengue vaccination in Brazil in 2024 (N = 1907/5570). A mixed-effects model was employed, with vaccination coverage as the dependent variable, vaccine type as the independent variable, and municipalities as a categorical random effect.

RESULTS

The HPV vaccine demonstrated substantially higher performance compared to the dengue vaccine, with a mean vaccination coverage of 91.28% and 68.74% of municipalities achieving ≥90% coverage. In contrast, the dengue vaccine showed a mean coverage of 29.76%, with 86.62% of municipalities reporting <50% coverage. Results from both crude and adjusted mixed-effects models confirmed that dengue vaccination coverage was significantly lower than HPV vaccination coverage, with an adjusted mean difference of -61.5% (95% CI: -62.3 to -60.6; p < 0.001).

CONCLUSION

HPV vaccination achieved high and homogeneous coverage within the recommended targets, while dengue vaccination faced significant challenges, with low coverage and high municipal variability. Factors such as vaccine hesitancy, logistical barriers, and record-keeping failures hindered its implementation. Localized strategies, educational campaigns, and improvements in information systems can help increase vaccination coverage.