Public Health Impact of Implementing the 20-valent Pneumococcal Conjugate Vaccine for Routine Paediatric Vaccination in Belgium

Abstract

Objective: In 2024, serotypes covered by 20-valent pneumococcal conjugate vaccine (PCV20) were among the most prevalent in invasive pneumococcal disease (IPD) in Belgium. This study assessed the public health impact of implementing PCV20 into Belgium’s paediatric national immunization programme (NIP) over 10 years and foregone public health benefits delayed PCV20 implementation versus the current standard of care – 13-valent PCV (PCV13).

Methods: A Markov structure comprising of active disease, non-disease, and death states estimated IPD, inpatient- and outpatient-pneumonia, and otitis media (OM) cases and deaths for each vaccine over 1, 2, and 10 years. This population-based study considered a vaccinated cohort (<2 years), and unvaccinated cohorts benefiting from indirect effects. The base-case included only individuals aged <18 years. Several scenarios were tested including indirect effect exclusion and exploring serotype replacement.

Results: Over 10 years, PCV20 was estimated to prevent 185,512 more disease cases and 30 more deaths versus PCV13. Delaying PCV20 implementation by one year resulted in 8,141 disease cases that could have been prevented, more than doubling in second year. PCV20 health gain was reduced in scenarios without indirect effects or with serotype replacement, though PCV20 remained favoured in all scenarios.

Conclusions: Paediatric PCV20 implementation could have greater public health benefit in Belgium compared to PCV13 and a 2-year delay in PCV20 implementation could result in substantial foregone public health gains. A limitation of this study is that the base case did not account for serotype replacement due to limited evidence, although scenario analyses suggest that the overall conclusions are robust.