Declines in Pneumonia Mortality Following the Introduction of Pneumococcal Conjugate Vaccines in Latin American and Caribbean Countries

Background. Pneumococcal conjugate vaccines (PCVs) are recommended for use in pediatric immunization programs world-wide. Few data are available on their effect against mortality. We present a multicountry evaluation of the population-level impact of PCVs against death due to pneumonia in children <5 years of age. Methods. We obtained national-level mortality data between 2000 and 2016 from 10 Latin American and Caribbean countries, using the standardized protocol. Time series models were used to evaluate the decline in all-cause pneumonia deaths during the postvaccination period while controlling for unrelated temporal trends using control causes of death. Results. The estimated declines in pneumonia mortality following the introduction of PCVs ranged from 11% to 35% among children aged 2-59 months in 5 countries: Colombia (24% [95% credible interval {CrI}, 3%-35%]), Ecuador (25% [95% CrI, 4%-41%]), Mexico (11% [95% CrI, 3%-18%]), Nicaragua (19% [95% CrI, 0-34%]), and Peru (35% [95% CrI, 20%-47%]). In Argentina, Brazil, and the Dominican Republic, the declines were not detected in the aggregated age group but were detected in certain age strata. In Guyana and Honduras, the estimates had large uncertainty, and no declines were detected. Across the 10 countries, most of which have low to moderate incidence of pneumonia mortality, PCVs have prevented nearly 4500 all-cause pneumonia deaths in children 2-59 months since introduction. Conclusions. Although the data quality was variable between countries, and the patterns varied across countries and age groups, the balance of evidence suggests that mortality due to all-cause pneumonia in children declined after PCV introduction. The impact could be greater in populations with a higher prevaccine burden of pneumonia.

Automated summary

A multi-country evaluation in Latin American and Caribbean countries showed that the introduction of pneumococcal conjugate vaccines led to a decline in pneumonia mortality among children aged 2-59 months in some countries. However, the impact varied across countries and age groups, suggesting the need for further research and monitoring of vaccine effectiveness.