Considerations for estimating real-world outcomes and value in vaccination: A case study with adult hepatitis B virus vaccination

Abstract

BackgroundIn the absence of field efficacy studies, estimating the real-world effectiveness of vaccines may consider immunogenicity from randomized controlled clinical trials and real-world adherence. Combining seroprotection rates (SPRs) with regimen completion rates gives an estimate of an effective vaccine protection rate (eVPR), which can be leveraged to evaluate real-world cost-effectiveness by linking it with vaccine costs to estimate the cost-per-protected patient (CPP). MethodsThis study evaluated eVPR and CPP as estimates of vaccine clinical- and cost-effectiveness of two-dose (HepB-CpG) and three-dose (HepB-Alum) hepatitis B virus (HBV) vaccines in the general adult population and a subpopulation with diabetes mellitus. eVPR was calculated from head-to-head SPR data from phase 3 clinical trials directly comparing HepB-CpG and HepB-Alum vaccine regimens and real-world head-to-head adherence data. CPP was calculated as the average cost of each regimen divided by eVPR. ResultsHigher eVPR in the adult population was achieved with HepB-CpG (68.0%) versus HepB-Alum (41.6%), reflecting the combination of higher SPR and vaccine regimen completion. The CPP for HepB-CpG ($331.31) was $45.67 (95% CI: $36.66, $55.19) less than HepB-Alum ($377.09). Greater savings were observed among persons with diabetes, with CPP $149.60 (95% CI: $80.29, $195.63) lower with HepB-CpG ($367.57) than HepB-Alum ($517.37). ConclusionsMetrics estimating vaccine real-world effectiveness and value may guide informed decisions in vaccine selection. For example, using eVPR and CPP, HepB-CpG represents a more effective, value-advantaged approach than HepB-Alum toward reducing HBV infection.