Cost-effectiveness of Haemophilus influenzae type b conjugate vaccine in low- and middle-income countries: regional analysis and assessment of major determinants

Abstract

Objectives: To estimate the cost-effectiveness of Haemophilus influenzae type b (Hib) conjugate vaccine in low- and middle-income countries and identify the model variables, which are most important for the result.

Study design: A static decision tree model was developed to predict incremental costs and health impacts. Estimates were generated for 4 country groups: countries eligible for funding by the GAVI Alliance in Africa and Asia, lower middle-income countries, and upper middle-income countries. Values, including disease incidence, case fatality rates, and treatment costs, were based on international country estimates and the scientific literature.

Results: From the societal perspective, it is estimated that the probability of Hib conjugate vaccine cost saving is 34%-53% in Global Alliance for Vaccines and Immunization eligible African and Asian countries, respectively. In middle-income countries, costs per discounted disability adjusted life year averted are between US$37 and US$733. Variation in vaccine prices and risks of meningitis sequelae and mortality explain most of the difference in results. For all country groups, disease incidence cause the largest part of the uncertainty in the result.

Conclusions: Hib conjugate vaccine is cost saving or highly cost-effective in low- and middle-income settings. This conclusion is especially influenced by the recent decline in Hib conjugate vaccine prices and new data revealing the high costs of lost productivity associated with meningitis sequelae.

Figure 1

Correlation between GNI per capita and costs of treating meningitis (2010 US$).

Figure 2

Correlation between GNI per capita and costs of treating severe pneumonia (2010 US$).

Figure 1

Model framework. a, Clinical pneumonia incidence in children aged <5 years. b, Percent of clinical pneumonia caused by Hib. c, Hib NPNM incidence in children aged <5 years. d, Hib meningitis incidence in children aged <5 years. e, Pneumonia CFR without access to care. f, Pneumonia CFR with access to care. g, Hib NPNM CFR without access to care. h, Hib NPNM CFR with access to care. i, Hib meningitis CFR without access to care. j, Hib meningitis CFR with access to care. k, Proportion of Hib pneumonia cases seeking care. l, Proportion of cases of Hib NPNM seeking care. m, Proportion of cases of Hib meningitis seeking care. n, Proportion of Hib meningitis survivors with disability. o, Proportion with cognitive difficulties only. p, Proportion with seizure disorders only. q, Proportion with hearing loss only. r, Proportion with motor deficit only. s, Proportion with visual disturbance only. t, Proportion with multiple disabilities. u, Proportion with clinical impairments only.

Figure 2

Histogram of Monte Carlo simulations for costs per discounted DALY averted.

Figure 3

Contribution to variance of uncertain variables.