Reactive strategies for containing developing outbreaks of pandemic influenza

Table 3 Average overall illness attack rates and total costs of interventions with 35% vaccination coverage

Intervention¹	Delay in Initiation of Vaccination²	No Post-initiation Vaccination Delays		Post-initiation Vaccination Delays³
听	听	Attack Rate (%)	Cost (US$m)	Attack Rate (%)	Cost (US$m)
None	听	34.1	81.1	听	听
A	听	31.3	75.9	听	听
S	听	24.0	125.0	听	听
A+S	听	9.2	48.0	听	听
V_L	Pre-vaccination	26.1	71.1	听	听
V_L	Reactive, no delay	28.8	77.7	28.8	77.7
V_L	30-day delay	29.0	78.1	29.5	79.3
V_L	60-day delay	30.7	82.2	32.2	86.0
V_M	Pre-vaccination	18.8	53.7	听	听
V_M	Reactive, no delay	22.6	62.8	22.8	63.1
V_M	30-day delay	23.0	63.7	24.6	67.5
V_M	60-day delay	27.3	74.1	30.8	82.5
V_L+A	Pre-vaccination	19.3	56.4	听	听
V_L+A	Reactive, no delay	25.2	70.6	25.3	70.8
V_L+A	30-day delay	25.4	71.1	25.7	71.8
V_L+A	60-day delay	26.2	72.9	27.1	75.0
V_M+A	Pre-vaccination	2.1	16.1	听	听
V_M+A	Reactive, no delay	8.1	30.1	10.0	34.3
V_M+A	30-day delay	12.4	40.2	15.8	48.2
V_M+A	60-day delay	18.6	54.7	20.8	60.1
V_L+S	Pre-vaccination	12.7	69.9	听	听
V_L+S	Reactive, no delay	17.3	93.6	17.5	95.7
V_L+S	30-day delay	17.8	96.5	18.3	99.0
V_L+S	60-day delay	18.6	101.9	19.6	108.8
V_M+S	Pre-vaccination	2.3	19.6	听	听
V_M+S	Reactive, no delay	6.8	41.6	8.5	49.4
V_M+S	30-day delay	9.9	56.3	15.4	87.3
V_M+S	60-day delay	13.4	74.7	17.9	95.7
V_L+A+S	Pre-vaccination	1.0	15.9	听	听
V_L+A+S	Reactive, no delay	3.9	29.2	4.5	32.2
V_L+A+S	30-day delay	4.6	32.6	4.9	34.2
V_L+A+S	60-day delay	4.8	33.8	5.4	36.8
V_M+A+S	Pre-vaccination	0.2	11.9	听	听
V_M+A+S	Reactive, no delay	0.5	13.1	0.8	14.9
V_M+A+S	30-day delay	1.2	16.6	1.6	18.6
V_M+A+S	60-day delay	2.0	20.2	2.4	22.0

1. Abbreviations for modeled interventions: V (vaccination of up to 35% of the population), L (low efficacy), M (moderate efficacy), A (antiviral treatment and household prophylaxis of up to 10% of the population), S (school closure and social distancing).
2. Initial supply-chain delays which prevent immediate initiation of vaccination programs after the intervention trigger occurs.
3. Additional supply-chain delays, after initiation of the vaccination program, as a result of which vaccines become available in three equal batches, spaced two weeks apart.

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