Cost-Minimization and Budget Impact Analysis of a Hexavalent Vaccine (Hexaxim®) in the Colombian Expanded Program on Immunization.

OBJECTIVES: To evaluate cost implications of a hexavalent vaccine (diphtheria, tetanus, and acellular pertussis [DTaP]-inactivated polio vaccine [IPV]-hepatitis B [HB]-Haemophilus influenzae type B [Hib] polysaccharide conjugated to T protein [PRP∼T]) as an alternative to DT-whole-cell pertussis (wP)-HB//Hib, DTwP, IPV, and oral polio vaccines in the Expanded Program on Immunization schedule in Colombia. METHODS: Primary vaccination (DTaP-IPV-HB-PRP∼T or DTwP-HB-Hib + IPV [2, 4, 6 months]) and booster (DTaP-IPV-HB-PRP∼T or DTwP + oral polio vaccine [18 months]) (scenario 1) and primary vaccination only (DTaP-IPV-HB-PRP∼T or DTwP-HB-Hib + IPV) (scenario 2) were evaluated. An estimated cost-minimization analysis was based on a micro costing technique for vaccination-associated activities. Adverse event (AE)-associated costs, out-of-pocket costs, and productivity losses for caregivers were included. A budget impact (12-month temporal horizon) was estimated according to the distribution of full-term and premature infants. A 5% annual discount rate was used. A 2-way univariate (tornado) analysis evaluated which variables had the greatest impact on the overall cost. RESULTS: DTaP-IPV-HB-PRP∼T resulted in a cost increase of 29.38% (scenario 1) and 22.19% (scenario 2) for full-term infants and a decrease of 0.99% (scenario 1) and 18.88% (scenario 2) for premature infants, probably because of the higher incidence of wP-related AEs and associated costs in premature infants. With a 100% replacement rate, the budget impact for full-term infants and full-term plus premature infants was 23.73% and 21.80% (scenario 1), respectively, and 13.02% and 11.14% (scenario 2), respectively, of the national immunization program budget. The variables with most impact were the hexavalent vaccine price and costs associated with the pentavalent safety profile. CONCLUSIONS: Incorporation of the hexavalent vaccine in the Expanded Program on Immunization schedule would lead to an increase in spending largely mitigated by reduced AE incidence and reduced logistic and social costs.