Fig. 4

Full range of relative risk in a influenza in the elderly (60+ years) and b rubella in women of childbearing age (15–45 years), due to differences in contact rate (χ= 0.6–0.9) as isolation between sub-groups varies (ξ = 0.05–0.15). Red shaded region shows range of relative risk with no vaccination, blue shaded region shows relative risk with vaccination at 80% of the critical vaccination threshold (37% coverage for influenza, 67% coverage for rubella)