The effects of vaccination, the incidence of the target diseases

As a result of improved socio-economic state and related hygiene, and the introduction of the National Vaccination Programme (RVP), the incidence of the target diseases of the RVP is low nowadays. Insight in the occurrence of the diseases remains necessary in order to be able to signal possible secondary effects at an early stage. The vaccination coverage is very high in the Netherlands, but considerable geographic differences exist within the country. Especially in municipalities where groups that reject vaccination on religious ground are clustered, the vaccination coverage is low. Herd immunity can be broken in socially and geographically clustered non-vaccinated groups. On the basis of the occurrence results of the target diseases of the RVP, we give recommendations for the future surveillance of the target diseases of the RVP and invasive meningococcal and pneumococcal infections. Besides continuation of the surveillance, additional research in case of outbreaks and epidemics is recommended, in order to obtain more insight into the circulation of the pathogens.