Significance To understand and mitigate the impact of climate change on host-parasite trophic interactions, we need to know how variation in immune responses among hosts can modify the effect of warming on infectious disease processes. By modeling the dynamics of infection of two parasite species in a rabbit population, we show that immunity can interact with climate. Specifically, the annual intensity of infection remains relatively constant over time, although younger hosts carry heavier infections in the summer in warming years. In contrast, in the second parasite the lack of immune control leads the intensity to increase with warming. Immunity can reduce the severity of population infection, but it can also exacerbate parasite intensity in the younger individuals exposed to climate warming.