Ring Vaccination

Ring vaccination is a strategy to inhibit the spread of a disease by vaccinating those most likely to be infected, targeting the contacts of confirmed patients and the people in close contact with those contacts, so that everyone who has been or could have been exposed to a patient receives the vaccine, creating a ring of protection that can limit the spread of a pathogen. The strategy requires thorough and rapid surveillance and epidemiologic case investigation, and the Intensified Smallpox Eradication Program used it with great success in eradicating smallpox in the latter half of the twentieth century.