Low-efficacy HIV vaccines: potential for community-based intervention programmes.

To combat the spread of HIV, progress on vaccine development is eagerly awaited. Haynes in this series has described the progress made so far with various vaccine types. This article describes how mathematical modelling techniques can be used to predict the likely impact of low-efficacy vaccines in community transmission of the virus. The answers are often not what one would predict by intuition alone, and they have great bearing on the likely success of such vaccination strategies.