The predicted probability of infection leading to death was under 0.001% in children under eleven years of age, rising to approximately 0.07% in fifty to sixty-four year olds. The corresponding risk of death increased considerably in the over sixty-four year olds, to approximately 9%, although
the greater part of this risk is likely to be concentrated in the oldest individuals. Paediatric vaccination of two to eighteen year olds, at coverage rates of 10%, 50% and 80%, reduced the simulated 17-AAG clinical trial mean annual number of general practice consultations resulting from influenza A and B infections in the entire population by 310,000 (37%), 690,000 (84%) and 790,000 (95%) respectively. Corresponding figures for hospitalisations were 8000 (34%), 19,000 (78%) selleckchem and 23,000 (94%) and for deaths were 6000 (33%), 15,000 (76%) and 18,000 (94%). An 80% coverage of 2–4 year olds reduced the mean annual number of consultations, hospitalisations and deaths in the entire population by 360,000 (44%), 10,000 (40%) and 7000 (36%). Vaccinating 10% of two to eighteen year olds is predicted to
avert an annual mean of 140,000 general practice consultations in this age group and a further 160,000 in the wider population, as a result of indirect protection (<2 years: 25,000; 19–49 years: 75,000; 50–64 years: 25,000; 65+ years: 36,000) (Fig. 5b). Increasing coverage of 2–18 year olds to 50% significantly increases the mean annual number of consultations averted, with 310,000 prevented by vaccination in the target age group and herd immunity preventing 390,000 more (<2 years: 56,000; 19–49 years: 187,000;
50–64 years: 60,000; 65+ years: 82,000). Further increasing the coverage to 80% of 2–18 year olds results in diminishing returns reflecting the pattern of infection, annually preventing a mean of 330,000 consultations in those age groups receiving the vaccine and herd immunity averting 463,000 additional consultations (<2 years: 63,000; 19–49 years: 223,000; 50–64 years: 74,000; 65+ years: 103,000). The corresponding figures for 10% coverage of 2–4 year olds were 185,000 consultations prevented in the targeted age groups, with Resminostat indirect protection averting a further 180,000 (<2 years: 32,000; 19–49 years: 80,000; 50–64 years: 28,000; 65+ years: 39,000). The skewed nature of the probability of hospitalisation or death with age, once infected with influenza, is apparent in the number of these outcomes averted by paediatric vaccination. Within those age groups targeted, vaccination of 10% of 2–18 year olds is estimated to prevent an annual mean of approximately 1000 hospitalisations (Fig. 5c) and fewer than 20 deaths (Fig. 5d). Herd immunity in the remaining population would prevent 7300 hospitalisations and 6500 deaths, of whom 5400 (74%) and 6100 (95%) respectively are in the elderly over 64 years of age.