Meningococcal infections (MI), caused by Neisseria meningitidis, are severe and potentially lethal. Introduction of the meningococcal C vaccine into the Programa Nacional de Imunizações (PNI) in 2010 sought to reduce these outcomes. This study aims to analyze the impact of vaccination on hospitalizations and deaths from meningococcal infections in Brazil between 2000 and 2022. Ecological, descriptive and retrospective study with data from the Sistema de Informações Hospitalares (SIH) and the PNI Information System (SI-PNI). Hospitalizations, deaths and vaccination coverage against meningococcal C were analyzed. Rates were calculated and Pearson correlation was used to assess the impact of vaccination. After introduction of meningococcal C vaccine into the national schedule, a consistent reduction in hospitalizations and deaths from MI was observed in Brazil. Between 2000 and 2022, the national hospitalization rate fell by 36%. The largest reductions were seen in the Southeast (-48.16%), Northeast (-33.22%) and North (-22.32%). In the South, in years with vaccination coverage ≥80%, there was a 19.14% reduction in hospitalizations. In children aged 0–4 years, the main target group, hospitalizations fell by 57%. The 5–9 and 10–14 age groups showed reductions of 51% and 39%, respectively. Young adults had smaller decreases, and in the ≥40-year groups there was an increase in hospitalizations, possibly because they were not included in childhood vaccination strategies. Hospital mortality also decreased in children: in those under 1 year, from 11.58 to 8.80 deaths per 100,000 hospitalizations; in those 1–4 years, from 10.97 to 7.02. Among those aged 70–79 years, mortality declined from 36.39 to 26.88. The Pearson correlation with a one-year lag between vaccination coverage and hospitalizations was negative and moderate in Brazil ( r = -0.56), reinforcing the national impact of vaccination. More expressive results were found in states such as Roraima ( r = -0.72), Amazonas ( r = -0.71), Paraíba ( r = -0.56) and Espírito Santo ( r = -0.55), indicating a consistent association between increased vaccination coverage and reduced hospitalizations for meningococcal infection. The meningococcal C vaccine reduced hospitalizations and mortality from meningococcal infection in Brazil, especially in children (up to 57%). The negative correlation between vaccination coverage and hospitalizations reinforces its effectiveness. The increase in hospitalizations among adults ≥40 years highlights the importance of continuous monitoring and maintaining vaccination within the PNI.
Zaleski et al. (Sun,) studied this question.