Table 3.

Initial conditions used for the US, UK and the Netherlands. Baseline estimates used in previous studies.

	US	UK	Netherlands
population size	298 444 215a	60 609 153a	16 491 461a
high-risk (%)	20	10	10
low-risk (%)	80	90	90
initial conditions
Sh, $S_{\ell }$	6×107, 2.4×108	6.1×106, 54.9×106	1.65×106, 14.85×106
$(E_{i_1})$, $E_{i_2}$	50, 50	50, 50	50, 50
$I_{i_1}$, $I_{i_2}$	1, 1	1, 1	1, 1
baseline from the literatureb
$\mathcal{R}$0	1.4–2.4	1.28–2.0	1.68–1.89
case-fatality percentage (%)	0.37–2.5	0.3–3	0.06–0.67
clinical attack rate (%)	25–50	30–50	30–50
hospitalization rate (%)	0.55	0.1	0.06–4

^aStatistics assessed: July 2006 (The World Factbook 2006).

^bEstimates obtained from the literature: US (Longini et al. 2004; Longini & Halloran 2005; Germann et al. 2006), UK (Gani et al. 2005) and the Netherlands (van Genugten et al. 2002, 2003).