Impact of universal Haemophilus influenzae type b vaccination starting at 2 months of age in the United States: an economic analysis

Objective. To evaluate the economic impact of universal Haemophilus influenzae type b (Hib) vaccination starting at 2 months of age.Methods. Decision-tree-based analysis was conducted of a hypothetical US birth cohort of 3 815 469 infants using population-based vaccination coverage and disease incidence data. All costs were estimated from both the direct cost (medical and nonmedical) and societal perspectives. Net present value, cost-effectiveness ratios, and benefit-cost ratios of the US Hib vaccination program were evaluated.Results. The results of these analyses showed that the universal vaccination program using the Hib conjugate vaccines in the United States in 2000 was cost-saving from both the direct and societal perspectives, with the benefit of the Hib vaccination program (net present value) from the direct cost and societal perspectives of $0.95 billion and $2.09 billion, respectively. Without a Hib vaccination program, the direct and societal costs of Hib invasive cases would be $1.35 billion and $2.58 billion, respectively. The direct and societal costs of the Hib vaccination program were estimated at $0.39 billion and $0.48 billion, respectively. The direct and societal benefit-cost ratios for the Hib vaccination program were 3.4 and 5.4, respectively. Varying the proportion of vaccines purchased and administered in the public versus the private sector and the proportion of combination vaccine versus monovalent vaccine administered did not have much effect on the results.Conclusions. Regardless of the perspective (direct cost or societal) and the assumptions used, the benefit-cost ratios of the US vaccination program are >1.0. Potential changes in the program, including use of more or less Hib combination vaccines, would not significantly alter the benefit-cost ratio. The national Hib vaccination program is highly cost beneficial and results in substantial cost savings.