The decrease in childhood vaccination coverage and its sociodemographic determinants, the Netherlands, birth cohorts 2008 to 2020.

INTRODUCTIONChildhood vaccination coverage has declined in recent years in many countries, including the Netherlands.AIMTo understand differences in coverage between population subgroups in the Netherlands over time, we studied sociodemographic factors associated with measles-mumps-rubella (MMR) and diphtheria-tetanus-pertussis-poliomyelitis (DTaP-IPV) vaccination.METHODSWe conducted a national retrospective database study including children born between 2008 and 2020. Individual-level data linkage allowed examination of associations of sociodemographic variables with MMR and DTaP-IPV vaccination status at age 2 years. We calculated coverage for each variable, stratified by birth cohort. Multivariable Poisson regression assessed independent associations and changes in coverage over time.RESULTSMMR coverage decreased in all population subgroups (overall 95% in cohort 2008 and 89% in cohort 2020), more substantially in some. In multivariable analysis, children of non-Dutch origin, particularly Moroccan and Turkish origin, showed more pronounced declines (respectively -25% and -12% as children of Dutch origin in cohort 2020). Among children not attending daycare and children living in larger families (≥ 4 children), coverage declined faster than in those attending daycare and living in smaller families (both -12% in cohort 2020). Coverage among children of self-employed mothers and children in the lowest income households was lower than among children of mothers in employment and the highest income households (respectively -8% and -7% in cohort 2020). Trends for DTaP-IPV vaccination were nearly identical.CONCLUSIONChildhood vaccination coverage in the Netherlands declined substantially, with increasing disparities between sociodemographic groups. Vaccination efforts should be prioritised to protect public health equitably.