Figure 3. Invasive Pneumococcal Disease (IPD) incidence in children <2 years old (per 100,000 children, per year) 5 years after the introduction of a conjugate vaccine, as a function of the frequency of capsular switch selected in vaccinated individuals, for a 90% vaccination coverage.

The origin of the cases (vaccine strains, non-vaccine strains, switched strains) is specified, and the expected incidence without vaccination is also depicted as a reference.