Reference no: EM133833894

Question

Many models are predicated on the idea that reaching herd immunity will stop transmission (at least for a short period of time). What are the implications of control of spread if COVID/SARS-CoV-2 does not match that model? There has been speculation about when in the coronavirus disease 2019 (COVID-19) pandemic we will be able to live with the virus in a manner that does not disrupt most peoples' lives. Much of this discussion has focused on herd immunity thresholds (Box 1). As commonly understood [1-7], herd immunity thresholds are reached when a sufficient proportion of the population is vaccinated or has recovered from natural infection with a pathogen such that its community circulation is reduced below the level of significant public health threat. For example, this threshold has been met with polio and measles circulation in the United States. Box 1. Herd Immunity Threshold A herd immunity threshold is the proportion of a population with immunity against a communicable disease agent (resulting from innate immunity, natural infection, or vaccination) above which transmission of the agent is largely prevented, except for sporadic outbreaks in undervaccinated or otherwise incompletely protected subsets of individuals. However, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2),