Assessing the impact of childhood pneumococcal vaccination on pneumonia mortality in Colombia: a 14-year analysis

Background: The 10-valent pneumococcal conjugate vaccine (PCV10) has been offered to all infants through Colombia’s National Immunization Program (NIP) since 2012, with catch-up vaccination until age 5. However, pneumococcal vaccination is not currently included in the NIP for other age groups, such as those ≥ 5 years with medical conditions or older adults. This study assessed the pediatric PCV10 effect on pneumonia mortality rate (MR) trends across different age groups from 2006 to 2019. Methods: This retrospective time-series study utilized the national death registration data. Deaths caused by pneumonia as the underlying cause of death were identified via ICD-10 codes and stratified by age groups (< 1, 1–4, 5–17, 18–49, 50–59, and ≥ 60 years). Crude MR, age-adjusted MR, and age-specific MRs per 100,000 population were calculated. Trends were assessed using joinpoint regression and expressed as annual percentage change (APC) and average APC in the pre-PCV10 (2006–2011), post-PCV10 (2013–2019), early post-PCV10 (2013–2016), and late post-PCV10 (2017–2019) periods. Results: From 2006 to 2019, there were 102,082 pneumonia-related deaths. The age-specific MR for infants < 1 year significantly decreased from 83.8 to 28.6 per 100,000 between 2006 and 2019 (APC:-6.9), while for children aged 1–4 years, it decreased from 9.3 to 3.8 (APC:-5.1). Other older age groups exhibited stable trends in the post-PCV10 period, except for adults aged ≥ 60 years, who had the highest age-specific MR (~ 112 per 100,000) over the study period, with an AAPC of 6.5% in the early post-PCV10 period, followed by stable trends in the late post-PCV10 period. The age-adjusted MR showed an increasing trend with an APC of 1.9% from 2008 to 2019. Conclusions: Our study found decreasing age-specific MR trends in children under 5 in the post-PCV10 period; however, no evidence of indirect benefits was seen in unvaccinated age groups older than 5 years. The findings underscore the need to expand pneumococcal vaccination programs to other age groups, mainly adults ≥ 60 years.