Cost-effectiveness of Haemophilus influenzae type b vaccine in Vietnam.

ABSTRACT

BACKGROUND: With GAVI support, Vietnam introduced Haemophilus influenzae type b (Hib) vaccine in 2010 without evidence on cost-effectiveness. We aimed to analyze the cost-effectiveness of Hib vaccine from societal and governmental perspectives. METHOD: We constructed a decision-tree cohort model to estimate the costs and effectiveness of Hib vaccine versus no Hib vaccine for the 2011 birth cohort. The disease burden was estimated from local epidemiologic data and literature. Vaccine delivery costs were calculated from governmental reports and 2013 vaccine prices. A prospective cost-of-illness study was conducted to estimate treatment costs. The human capital approach was employed to estimate productivity loss. The incremental costs of Hib vaccine were divided by cases, deaths, and disability-adjusted life years (DALY) averted. We used the WHO recommended cost-effectiveness thresholds of an intervention being highly cost-effective if incremental costs per DALY were below GDP per capita. RESULT: From the societal perspective, incremental costs per discounted case, death and DALY averted were US$ 6252, US$ 26,476 and US$ 1231, respectively; the break-even vaccine price was US$ 0.69/dose. From the governmental perspective, the results were US$ 6954, US$ 29,449, and US$ 1373, respectively; the break-even vaccine price was US$ 0.48/dose. Vietnam's GDP per capita was US$ 1911 in 2013. In deterministic sensitivity analysis, morbidity and mortality parameters were among the most influential factors. In probabilistic sensitivity analysis, Hib vaccine had an 84% and 78% probability to be highly cost-effective from the societal and governmental perspectives, respectively. CONCLUSION: Hib vaccine was highly cost-effective from both societal and governmental perspectives. However, with GAVI support ending in 2016, the government will face a six-fold increase in its vaccine budget at the 2013 vaccine price. The variability of vaccine market prices adds an element of uncertainty. Increased government commitment and improved resource allocation decision making will be necessary to retain Hib vaccine.