Fig. 1

Projected incidence and serotype distribution per 100,000 persons at the age of 65 years in the Netherlands over time in case of the continuation of PCV10 (no indirect effects) or after applying indirect effects from a switch to PCV13, PCV15, or PCV20 in childhood vaccination. Indirect effects encompass 80% indirect protection for serotypes added to PCV10 (starting 1 year after the switch and completed 8 years after the switch), with pneumococcal incidence levels returning to pre-indirect effects level due to serotype replacement (starting 3 years after the switch and completed 8 years after the switch). After 8 years, the incidence and serotype distribution remained stable for the rest of the time horizon. The split into serotype categories is based on Dutch serotype distribution data from 2019, when no programmatic pneumococcal vaccination occurred in the Netherlands. Serotype per category PCV10: 4, 6B, 9V, 14, 18C, 19F, 23F, 1, 5, 7F; PCV13-PCV10 + ST6C: 3, 6A, 19A, 6C (cross-protection via 6A), PCV15-PCV13: 22F, 33F, PCV20-PCV15: 8, 10A, 11A, 12F, 15B; PPV23-PCV20: 2, 9N, 17F, 20; PCV21-PCV20/PPV23: 15A, 15C, 16F, 23A, 23B, 24F, 31, 35B; PCV, pneumococcal conjugate vaccine; PPV, pneumococcal polysaccharide vaccine; IPD, invasive pneumococcal disease