Two ways to survive infection: what resistance and tolerance can teach us about treating infectious diseases

These authors express their opinion that we should devote more research attention to uncovering the mechanisms by which a host can tolerate, as well as resist, infection with a pathogen. New drugs to increase tolerance to infection should provide therapies to which pathogens will not develop resistance. A host can evolve two types of defence mechanism to increase its fitness when challenged with a pathogen: resistance and tolerance. Immunology is a well-defined field in which the mechanisms behind resistance to infection are dissected. By contrast, the mechanisms behind the ability to tolerate infections are studied in a less methodical manner. In this Opinion, we provide evidence that animals have specific tolerance mechanisms and discuss their potential clinical impact. It is important to distinguish between these two defence mechanisms because they have different pathological and epidemiological effects. An increased understanding of tolerance to pathogen infection could lead to more efficient treatments for infectious diseases and a better description of host–pathogen interactions.