Immunization governance: Mandatory immunization in 28 Global NITAG Network countries

International trends currently favour greater use of mandatory immunization. There has been little academic consideration or comparison of the existence and scope of mandatory immunization internationally. In this paper, we examine mandatory immunization in 28 Global NITAG (National Immunization Technical Advisory Group) Network (GNN) countries, including countries from every WHO region and World Bank income level classification. We found that although mandatory immunization programs, or mandatory elements within broader immunization programs, are relatively common, jurisdictions vary significantly with respect to the immunizations required, population groups affected, grounds for exemptions, and penalties for non-compliance. We also observed some loose associations with geography and income level. Based on these data, we categorized policies into a spectrum ranging from Narrow to Broad scope.