More From Less: Optimising Vaccines in a Constrained World

This paper argues that more focus on how vaccines are dosed can deliver large benefits. The current practice of vaccine development and licensure delivers vaccines that are safe and effective, but can lead to doses that are higher than is socially optimal. After a vaccine has been approved, there are often few commercial incentives to make adjustments. As a result, while there are many successful examples of adjusting dosing, this process can take decades. This is especially important in pandemics and under supply and fiscal constraints, such as those currently facing Gavi. A simple analysis suggests that there are both large health and fiscal benefits that public health decision makers and vaccine buyers can get from optimisation. This is shown in three illustrative but concrete cases: accelerating the switch to single-dose HPV vaccination, adjusting PCV dosing, and dose-sparing for a COVID-19 vaccine. To get to optimal vaccines faster, all stakeholders in vaccine development need to contribute. Researchers and pharmaceutical companies should improve the science of vaccine dosing, especially through greater focus on model-informed development. Regulators should push for optimisation data as part of approvals and consider clinical trial designs that enable optimisation. Global health funders and vaccine buyers should identify vaccines where more evidence is needed and be proactive about generating it, possibly by creating new funding models and pull incentives for optimisation.