Quantifying vaccine dissemination for uptake comparisons between vaccines.

Vaccine hesitancy is a complex public health concern, but it has been difficult to characterize and monitor the speed of uptake of individual vaccines. The study was aimed to determine whether vaccine uptake can be quantified and mapped to individual vaccines and to consider methods for comparing vaccine uptake between vaccines. Vaccines assessed were selected based on their similarity to COVID-19 and the 2020 pandemic by the following criteria: the vaccine impacts the broader public and has global health effects, was approved between 2006 and 2024, protects against a virus, and does not follow a seasonal pattern, unless it had a significant outbreak between 2006 and 2024 before it became a seasonal vaccine. Main outcomes included diffusion curves of each vaccine, both in terms of estimated global units dispensed and estimated proportion of the US population that is vaccinated. Metrics included average units dispensed globally per month, mean coverage of the target population, maximum coverage of the target population, and rate of change in number of vaccinations over time. Metrics are estimates which rely on sales data and imputation. Diffusion curves were mapped for individual vaccines, and five vaccines were determined to have the fastest relative uptake, although not all differences were statistically significant. The five vaccines were Arexvy, Comirnaty, Gardasil/Gardasil 9, Heplisav-B, and the ID Biomedical H1N1 Monovalent Vaccine. Collection, mapping, and analysis of estimated vaccine diffusion curves inform understanding of vaccine hesitancy and the impact of strategies and tactics to improve and accelerate vaccine uptake.