Pneumococcal conjugate vaccine and pneumonia prevention in children with congenital heart disease

Abstract

Background: A successful strategy to prevent Streptococcus pneumoniae infections is the administration of pneumococcal conjugate vaccines (PCVs). Objective: To analyze the effectiveness of the 7- and 13-valent PCV for the prevention of all-cause pneumonia. Materials and Methods: A retrospective cohort of children younger than 5 years of age, with congenital heart disease (CHD) and different vaccination schedules, was analyzed. History of vaccination was confirmed with verifiable records. The outcome measure was all-cause pneumonia or bronchopneumonia. Protocol was approved by the Institutional Review Board. For comparisons, we used inferential statistics with Chi-square and Fisher's exact test; a p ≤ 0.5 was considered statistically significant. Relative and absolute risks reduction and number needed to treat were also calculated. Results: A total of 348 patients were included: 196 with two or more doses of PCV (considered the vaccinated group), and 152 in the unvaccinated group. There was a statistically significant difference for pneumonia events (p < 0.001) between the vaccinated (26/196) and unvaccinated (51/152) groups. The relative risk reduction was 60.5%, and the absolute risk reduction, 20.3%. There were no differences between patients who received two, three or four doses. The number needed to vaccinate to prevent one event of pneumonia was 5 children. Conclusions: At least two doses of PCV in children with CHD reduced the risk of all-cause pneumonia.