Cost-effectiveness of Pharmaceutical- based Pandemic Influenza Mitigation Strategies

The states are vector structures containing 12 elements representing 3 possible vaccination groups (no-vaccine (i=1), pre-vaccine and matched vaccine (i=2) or matched vaccine only (i=3)) and 3 population groups (0-19 years (j=1), 20-64 years (j=2), and 65+ (j=3)). Susceptible states, for example, can be written as Si, i,j=1..3. The parameters ω and γ were fixed constants representing the rate of progression from exposure to becoming infectious and the rate of recovery from infection respectively. Births and deaths were assumed to make a negligible contribution over the time-scale of the epidemic. We also assumed that there are a growing number of imported cases during the early stages of the pandemic (discussed below). See Appendix 2 for parameter values and ranges.