Figure 1From: Contingency planning for a deliberate release of smallpox in Great Britain - the role of geographical scale and contact structure Disease states of the model, and processes connecting them. These are: S susceptible; S V susceptible and not contraindicated for vaccination; E latent; P prodromal; I infectious; R removed; Q isolated; O susceptible under observation; E T latent under observation; V vaccinated. The latent class is populated by transmission from infectious or prodromal cases to susceptibles.Back to article page