title: Understanding Herd Immunity.
abstract: Individual immunity is a powerful force affecting host health and pathogen evolution. Importantly, the effects of individual immunity also scale up to affect pathogen transmission dynamics and the success of vaccination campaigns for entire host populations. Population-scale immunity is often termed 'herd immunity'. Here we outline how individual immunity maps to population outcomes and discuss implications for control of infectious diseases. Particular immunological characteristics may be more or less likely to result in a population level signature of herd immunity; we detail this and also discuss other population-level outcomes that might emerge from individual-level immunity.
authors.affiliation: Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA; Office of Population Research, Woodrow Wilson School, Princeton University, Princeton, NJ, USA. Electronic address: cmetcalf@princeton.edu.
authors.forename: C J E
authors.initials: CJE
authors.lastname: Metcalf
authors.affiliation: Centre of Infectious Disease Dynamics, Pennsylvania State University, University Park, PA, USA.
authors.forename: M
authors.initials: M
authors.lastname: Ferrari
authors.affiliation: Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA.
authors.forename: A L
authors.initials: AL
authors.lastname: Graham
authors.affiliation: Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA; Office of Population Research, Woodrow Wilson School, Princeton University, Princeton, NJ, USA.
authors.forename: B T
authors.initials: BT
authors.lastname: Grenfell
mesh_terms: D003141:Communicable Diseases / Q000276:immunology; D006801:Humans; D032521:Immunity, Herd / Q000276:immunology*