Evaluation of the direct and indirect impact on pneumonia hospitalization after almost a decade of the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine in Brazil

Evaluation of 10-valent pneumococcal vaccine on pneumonia hospitalization in Brazil

Abstract

Introduction: Pneumococcal pneumonia is a leading cause of severe disease, leading to approximately 2.2 million hospital admissions in 2019 in Brazil. Since 2010, the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine was introduced in Brazil as part of the National Immunization Program (NIP) with free-for-all access, approaching coverage of 91.4% in 2019. Although studies from many countries are available, there is still a need to understand the effect of the vaccine introduction on the incidence of pneumonia hospitalizations in Brazil.

Methodology: We accessed data on hospitalization associated with the diagnosis of pneumonia in the population assisted by the Brazilian Public Health system to fit a time series analysis testing the main hypothesis of the influence of vaccination on the trends for the incidence of pneumonia hospitalizations .

Results: The post-vaccination period showed a negative trend, reducing 1.75, 0.16, and 0.11 cases per 100,000 inhabitants per month for the groups <1 year, 1-4 year, and 5-9 year, respectively. In age groups larger than 20 years, the post-vaccination period has a positive trend, but not as great as compared trends before the vaccination period. These results point to a protective herd effect in the elderly population nine years after introducing the pneumococcal vaccine in the NIP.

Conclusions: The universal vaccination has been shown to reduce hospitalizations associated with pneumonia diagnosis both in the vaccinated and non-vaccinated population in a sustained and progressive manner.