a1 Microbial Risk Assessment, Health Protection Agency, Centre for Emergency Preparedness and Response, Porton Down, Wiltshire, UK
To determine the potential benefits of regionally targeted mass vaccination as an adjunct to other smallpox control strategies we employed a spatial metapopulation patch model based on the administrative districts of Great Britain. We counted deaths due to smallpox and to vaccination to identify strategies that minimized total deaths. Results confirm that case isolation, and the tracing, vaccination and observation of case contacts can be optimal for control but only for optimistic assumptions concerning, for example, the basic reproduction number for smallpox (R0=3) and smaller numbers of index cases (∼10). For a wider range of scenarios, including larger numbers of index cases and higher reproduction numbers, the addition of mass vaccination targeted only to infected districts provided an appreciable benefit (5–80% fewer deaths depending on where the outbreak started with a trigger value of 1–10 isolated symptomatic individuals within a district).
(Accepted November 01 2006)
(Online publication January 12 2007)
c1 Author for correspondence: Mr J. R. Egan, Microbial Risk Assessment, Health Protection Agency, Centre for Emergency Preparedness and Response, Porton Down, Wiltshire, SP4 0JG, UK. (Email: firstname.lastname@example.org)
The views and opinions expressed in this paper are those of the authors and do not necessarily reflect those of the Department of Health for England, the European Union Directorate General for Health and Consumer Protection (DG SANCO), the Engineering and Physical Sciences Research Council or the Health Protection Agency.