Economic Evaluation of Childhood 7-Valent Pneumococcal Conjugate Vaccination in Korea

Abstract

BACKGROUND: Streptococcus pneumoniae (sp) is a leading cause of invasive and noninvasive bacterial disease in children. 7-valent pneumococcal conjugate vaccine (PCV-7) has been shown to significantly reduce the incidence of pneumococcal diseases, such as meningitis, bacteremia, pneumonia, and otitis media. Although PCV-7 was introduced in Korea in 2003, it is not yet included in the universal immunization program. OBJECTIVE: To evaluate the health outcomes, costs, and cost-effectiveness of universal vaccination with PCV-7 in Korean infants and to estimate the break-even price for PCV-7 from a societal perspective. METHODS: A decision analytic model was used to evaluate the cost-effectiveness of immunization with PCV-7 in a birth cohort of Korean infants born in 2006. A universal vaccination strategy was compared with no vaccination in terms of costs and life years gained (LYG) over a 5-year time horizon. The birth cohort size, incidence of disease, resource utilization, and associated costs were obtained from the Korea National Statistical Office, the Korean Centers for Disease Control and Prevention, the Korean National Health and Nutrition Examination Survey, and the Korean Ministry of Health and Welfare. Inputs on the probabilities of clinical treatment pathways (e.g., tympanostomy) were derived from international literature if data specific to Korea did not exist. To estimate the benefits of universal immunization, the serotype-specific efficacy of PCV-7 was derived from studies conducted by Northern California Kaiser Permanente and by the Finnish Otitis Media Vaccine Study and applied to the serotypes isolated in Korean children with sp infections. The effects of vaccination on quality of life, herd immunity, benefits after the first 5 years of life, and patient copayments were not considered. A 4-dose schedule was used in the base-case analysis. A 3-dose schedule was also evaluated. The assumed price per dose was Korean won (KW) 70,000 (approximately US$54; 2009 exchange rate US$1 = KW1,300). Univariate and probabilistic sensitivity analyses were performed. RESULTS: Implementing a 4-dose universal PCV-7 vaccination strategy in a birth cohort of 451,514 infants in Korea would prevent 96,728 cases of pneumococcal-related infections (591 meningitis, 1,379 bacteremia, 43,950 pneumonia, and 50,808 otitis media cases) and 218 deaths (199 discounted deaths averted, 575 discounted LYG over 5 years). The medical and non-medical cost burden of pneumococcal diseases offset with vaccination was KW44,033 million (US$33.87 million). The incremental discounted cost of universal vaccination was estimated to be KW86,384 million (US$66.45 million). The incremental cost per LYG was KW150.2 million (US$115,549) for the 4-dose schedule and KW103.91 million (US$79,955) for the 3-dose schedule. The break-even costs were KW22,100 and KW28,100 per dose for the 4- and 3-dose schedules, respectively. CONCLUSIONS: Universal PCV-7 vaccination of infants in Korea could substantially reduce pneumococcal disease morbidity, mortality, and related costs by preventing pneumococcal infections. However, at current market prices for the vaccine, a universal vaccination strategy is not cost-effective. The literature suggests that factors not considered in this analysis, including vaccine price reduction and indirect effects on public health (e.g., herd immunity), have the potential to make the public health impact and cost-effectiveness of universal PCV-7 vaccination in Korea more favorable.