Forecasting demand for Hib-containing vaccine in the world's poorest countries: a 4-year prospective experience.

This article analyzes the performance of a Hib vaccine demand forecast developed in 2003 for 68 GAVI-supported countries between 2004 and 2007. During that period of time, corresponding to an acceleration of Hib vaccine uptake, several groups of countries were identified based on the stage of their decision-making process, perception of Hib disease burden and programme performance. Better forecast accuracy was obtained for countries having already introduced the vaccine or that were about to do so. The ability to anticipate global needs in terms of vaccine volumes was highly dependant on the actual year of introduction of a small number of very large countries.