Table 1.
Attributes of rabies post-exposure vaccination regimens.
Figure 1.
Simulation framework for determining vaccine use under different PEP regimens and model inputs.
Framework for exploring different model inputs (detailed in Table 3) including degree of patient compliance, types of vaccine vials and levels of vaccine waste.
Table 2.
Costs associated with PEP vaccination.
Table 3.
Model inputs and sensitivity analyses conducted during simulations.
Figure 2.
Cost of vaccination per rabies death averted for different PEP regimens according to clinic throughput.
Costs for IM administered vaccinations (the Zagreb regimen and the Essen 4-dose reduced regimen are exactly equivalent and shown in black) and ID administered vaccinations (the updated TRC regimen is shown in blue, the 4-site in red, and the 1-week in grey) per rabies death averted is plotted against clinic throughput (the number of new animal bite patients presenting for PEP vaccination each month). Shading represents 99% confidence intervals resulting from variation in patient arrival dates and the effects on vial sharing. Dashed lines highlight optimal vaccine use in high throughput clinics. Panel A is based on 0.5 mL vials and panel B on 1 mL vials. Here, we assume that vaccine is perfectly delivered without any wastage (5 complete 0.1 mL injections from a 0.5 mL vial, and 10 complete 0.1 mL injections from a 1 mL vial), but we show the reductions in efficiency assuming some wastage in Figure S1. Note the x-axis is plotted on a log scale.
Table 4.
Annual estimated costs of PEP vaccination per clinic and savings from different pricing strategies.
Figure 3.
Clinic monthly savings and losses from ID administration of PEP under different pricing mechanisms.
A & E) patients are charged $2.5 per injection (25% of vial costs assuming a single vial costs $10) as well as a consultation fee and materials costs (see Table 4 for the costs from the perspective of the bite victim). B & F) patients are charged $3 per injection (30% of vial costs) as well as a consultation fee and materials costs. C & G) patients are charged a flat rate of $15 for the full PEP course (the cost of 1.5 vials) as well as a consultation fee and materials costs. D & H) patients are charged a flat rate of $20 for the full PEP course ($10 for each of the first two clinic visits, equivalent to two vials) as well as a consultation fee and materials costs. A, B, C, & D) compare regimens across a range of patient throughputs (from very low to very high, 1–1000 patients per month). E, F, G & H) are a closer examination of costs in low throughput clinics (1–50 patients per month). Blue lines indicate the updated TRC ID, red lines indicate the 4-site ID and gray lines indicate the 1-week ID regimens respectively, with solid lines corresponding to 0.5 mL vials and dashed lines corresponding to 1 mL vials. The pricing strategies shown would all result in substantial losses for IM delivered PEP vaccination (not shown).
Table 5.
Costs of PEP vaccination regimens from the bite-victim perspective.
Figure 4.
Effects of compliance on PEP effectiveness in preventing rabies and cost-effectiveness per death averted.
A) Additive protective efficacy of PEP (defined in Table 3) given 50% compliance is plotted against cost-effectiveness per rabies death averted, calculated from direct medical costs (Table 2). The different regimens are indicated as follows: reduced 4-dose Essen IM regimen in thick black, Zabreb IM in thin black, updated TRC ID in blue, 4-site ID in red and 1 week ID in gray. The dashed lines correspond to complete compliance. Here we assume use of 0.5 mL vials and clinic throughput of 100 new bite patients per month. Assuming use of 1 mL vials results are qualitatively similar but more cost-effective. B) Additive protective efficacy of PEP regimens (Table 3) is plotted against the percentage of rabies deaths averted at high (100%, dotted lines), moderate (75%, dashed lines) and poor (50%, solid lines) levels of compliance. Thick lines correspond to regimens requiring 4 clinic visits (reduced Essen 4-dose IM, updated TRC ID) and thin lines correspond to regimens requiring 3 clinic visits (Zagreb IM, 4-site ID, 1-week ID). C) The costs of PEP regimens for bite victims according to different pricing strategies (Table 5) are plotted against the risk of developing rabies assuming 75% additive protective efficacy for each PEP visit and assuming that patient compliance is affected by PEP costs (as described in Table 3).