Publication
Current practice in the design and evaluation of control measures in disease ecology and epidemiology, including vaccination, is largely based on reproduction numbers (RNs), which represent prognostic indices of long‐term disease transmission, both in naïve populations (basic RN) and in the presence of prior exposure or infection containment interventions (effective RN). A standard control objective is to establish herd immunity, for example by immunizing enough susceptible individuals to achieve RN < 1. However, achieving this goal may not be sufficient to avoid transient subthreshold outbreaks. Starting from simple metrics originally designed to analyse transient dynamics in population ecology, we propose an analytical framework based on RNs to determine sufficient conditions to prevent transient epidemic dynamics in epidemiological and disease ecology models. Specifically, we consider a general SIR model with age‐of‐infection structure, here applied to respiratory viruses in humans, and a stage‐structured model for tick‐borne zoonoses. We show that preventing transient outbreaks requires stricter RN thresholds than simply maintaining RN < 1. For viral respiratory diseases, epidemicity‐curbing RN thresholds vary between 0.10 (rubella) and 0.51 (MERS). For tick‐borne infections, the RN threshold is