Table 1.
Summary of key model parameters.
| Parameter | Value | Range | Reference |
|---|---|---|---|
| I. Epidemic parameters | |||
| Number of sex acts per year | 95–120 | 55 | |
| Proportion of sex acts protected by condom | 20% | 56 | |
| Condom efficacy | 70% | 57 | |
| Infection probability per act by HIV stage and CD4 count: | Estimated58; see also Supplementary Information | ||
| Acute stage | 5.5% | ||
| Recent infections and asymptomatic stage (CD4 > 500) | 0.21% | ||
| Asymptomatic stage (CD4 350–500) | 0.06% | ||
| Asymptomatic stage (CD4 200–350) | 0.11% | ||
| Symptomatic stage (CD4 < 200) | 0.33% | ||
| Efficacy of antiretroviral therapy (ART) in reducing infectiousness | 73–99% | 59 | |
| Vaccine coverage | 20% | 20% or 50% | Assumed |
| Average vaccine efficacy (VE) in reducing susceptibility over a 2-year period | 70% | 50% or 70% | Assumed7,15 |
| Proportion of vaccinated population responding to the vaccine | 72% | HVTN 702 protocol | |
| II. Economic parameters | |||
| Costs per programmed dose, totala | $30 | ||
| Vaccine price | $15 | $1–$30 | Assumed with reference pricing39 |
| Supply chain | $0.60 | 39 | |
| Service deliveryb | $5.07 | $1–$10 | 60 |
| HIV test, facility-based | $9.30 | $5–$15 | 61,62 |
| Cost of HIV treatment per year, total | $718 | $648–$789 | 54 |
| ART | $191 | $172–$210 | 54 |
| Personnel | $352 | $317–$387 | 54 |
| Labs | $107 | $97–$118 | 54 |
| Other | $68 | $62–$75 | 54 |
| Utility weights (health state) | Estimated49 | ||
| Acute HIV | 0.800 | 0.702–0.935 | |
| CD4 count > 350 | 0.935 | 0.821–1.0 | |
| CD4 count 200–349 | 0.818 | 0.723–0.912 | |
| CD4 count < 200 | 0.702 | 0.567–0.837 | |
| Discount rate | 3% | 0–5% | 44,52 |
aCosts adjusted to 2017 USD.
bCosts of delivery per vaccine dose include needle, syringe and alcohol swab for administration.