Abstract
Individuals vary in their immune response and, as a result, some are more susceptible to infectious disease than others. Little is known about which components of immune pathways are responsible for this variation, but understanding these underlying processes could allow us to predict the outcome of infection for an individual, and to manage their health more effectively. In this study, we describe transcriptome-wide variation in immune response (to a standardised challenge) in a wild population of field voles (Microtus agrestis). We find that this variation can be categorised into three main types. We also identify markers, across these three categories, which display particularly strong individual variation in response. This work shows how a simple standardised challenge performed on a natural population can reveal complex patterns of natural variation in immune response.