OBJECTIVES: Pneumococcal disease remains one of the most common vaccine-preventable diseases worldwide, causing invasive pneumococcal disease (IPD) and non-invasive disease such as pneumonia and otitis media (OM). The introduction of pneumococcal conjugate vaccines (PCVs) in pediatric national immunization programs (NIPs) have had a substantial impact from widespread use, however disease burden remains due to non-PCV serotypes. In Spain, where the 13-valent vaccine (PCV13) is part of the infant NIP, PCV13 serotypes cause 16.13% of residual IPD burden in 2019 in children <2 years old. The 15-valent (PCV15) serotypes cause 8.45% of residual burden, while 20-valent (PCV20) serotypes account for 31.82% of residual burden. The objective of this study is to determine the public health impact of switching from PCV13 to PCV15 or PCV20 in Spain’s infant NIP.

METHODS: A decision-analytic forecasting model was adapted to compare the health impact of switching infant vaccination from PCV13 to either PCV15 in 2023 or PCV20 in 2024. The model uses historical age and serotype-specific real-world data in Spain between 2013 and 2019 to project future IPD incidence for the population. Future PCV15-13 and PCV20-13 serotype trends from 2024 to 2028 are forecasted using the overall average historical PCV13-7 serotype trends between 2013 and 2019 in Spain. Future non-invasive disease incidence rates are assumed to vary proportionally with IPD.

RESULTS: Compared to PCV15, switching to PCV20 is estimated to prevent an additional 1,784 IPD cases, 38,834 pneumonia cases, 22,934 OM cases, amounting to a total of 63,552 pneumococcal disease cases and 761 pneumococcal related deaths over 5 years across all ages.

CONCLUSIONS: Replacing PCV13 with PCV20 is estimated to provide greater health impact compared to PCV15 in Spain, given PCV20’s incremental serotype coverage. PCV20 has the potential to reduce the disease burden by targeting additional serotypes that are not currently covered in the pediatric population.