Table 5.

Effects of pre-vaccination.

Country	Relative reduction in epidemic size, %a
	Pre-vaccination 20%	Pre-vaccination 30%	Pre-vaccination 50%
China	27.3 to 28.2	46.3 to 48.2	98.9 to 99.3
Hungary	23.2 to 24.4	38.6 to 39.2	87.9 to 90.0
United States	20.5 to 21.8	35.2 to 36.2	92.4 to 95.5
Canada	21.5 to 22.6	37.5 to 38.3	93.4 to 95.6
Italy	23.0 to 24.4	38.3 to 39.0	90.2 to 91.8
Japan	23.4 to 26.8	38.1 to 40.1	85.5 to 89.8
Israel	22.9 to 24.8	37.8 to 38.8	84.3 to 86.4
France	22.0 to 24.2	36.6 to 38.1	84.4 to 86.8
Sweden	23.1 to 24.8	38.2 to 39.0	86.3 to 88.6
UK	22.2 to 24.6	36.6 to 38.4	84.7 to 88.4
Germany	22.6 to 24.2	37.7 to 38.6	88.9 to 90.6
Portugal	22.7 to 24.5	37.1 to 38.6	88.3 to 92.4
Finland	22.9 to 24.7	37.7 to 38.7	84.5 to 87.3
Austria	21.6 to 23.5	35.8 to 37.1	81.7 to 84.1
Ireland	22.0 to 24.0	36.2 to 37.6	83.0 to 86.6
Denmark	21.5 to 23.5	35.6 to 37.1	81.7 to 85.0
Turkey	26.5 to 27.0	46.4 to 49.6	95.4 to 95.8
Iceland	20.6 to 24.8	33.9 to 38.6	78.8 to 87.8
Belgium	23.2 to 24.8	38.6 to 39.4	89.1 to 91.1
Slovenia	21.5 to 23.3	35.3 to 36.8	76.4 to 81.1
Netherlands	21.7 to 24.7	36.3 to 38.4	85.5 to 89.5
Switzerland	21.0 to 24.0	34.4 to 36.8	77.5 to 81.9
Spain	22.4 to 23.7	37.7 to 39.0	91.7 to 93.7
Greece	23.2 to 24.8	38.6 to 39.5	86.1 to 87.7
Tunisia	24.5 to 25.7	41.0 to 42.1	90.9 to 92.0
Czech Republic	24.8 to 25.6	42.0 to 44.9	89.7 to 90.6
Norway	23.1 to 24.7	37.9 to 38.9	85.9 to 88.7

^aRelative reduction of the epidemic size, using different hypothetical pre-vaccination scenarios, in the countries of the northern hemisphere in which vaccines were available during the 2009 to 2010 winter season. The relative reduction in the epidemic size was calculated as the relative reduction of the maximum of the 95% reference range, obtained from 2,000 stochastic realizations, in the reference stochastic forecast output set.