Relevance of Vaccine Literacy Assessment Tools

The systematic review by Zhang et al. recently published on IJPH provides an important update on the status of vaccine literacy (VL) and related measurement tools. While the Authors highlight the role of VL in overcoming vaccine hesitancy and increasing immunization rates, they also conclude that the tools used in the selected studies were “limited” in relation to the complexity of the influencing factors, as they were not designed to specifically assess VL skills, but were adapted from those used to measure health literacy (HL) in chronic patients. Indeed, many and complex determinants influence VL, similar to HL where the role of individual, societal and environmental factors is still being explored, sometimes seen as moderating, sometimes as mediating. The same role of HL in mediating health outcomes has been under discussion. For VL this complexity seems even greater, given its relative novelty, and because it refers to a specific but broad science, “vaccinology,” addressing the domains of disease prevention and health promotion, and entailing the many topics related to vaccines, not only immunological and epidemiological, but also regulatory and social, including communication, economics, and ethics. Vaccinology has developed rapidly and massively in recent years, and has been defined differently, although an overarching definition is still being discussed. All these aspects show why the VL tools used to date may appear limited, especially when compared with more consolidated HL measures.