Vaccines are one of the most successful and cost-effective public health interventions ever. Yet vaccine coverage is threatened by a persistent proportion of parents declining, delaying or unable to access vaccines, evident in intermittent recent outbreaks of vaccine-preventable diseases in New Zealand, Australia, Europe, and the Americas. While several tools (e.g. surveys/questionnaires) exist to measure vaccine acceptance or confidence, few are rigorously validated and none have been validated with New Zealand's diverse populations. No validated tool currently exists that is (i) brief, accurate and predictive of uptake to inform targeted interventions and campaigns in New Zealand, and (ii) able to both robustly measure and monitor vaccine acceptance and identify practical barriers limiting vaccine access. In a three-phase study, Australian colleagues and WHO collaborators are developing the first comprehensive, interlinked model of influences on parental acceptance and access to childhood vaccination: the VBAT. This application seeks funding for the New Zealand arm.