Table 1. Characteristics of four vaccine trial designs for dengue vaccines, in addition to our virtual trial.
| Variable | Sanofi CYD14 [28] | Sanofi CYD 15 [30] | Takeda [5,32] |
Butantan [4,31] |
Virtual trial |
|---|---|---|---|---|---|
| Sample size | 10,278 | 20,875 | 20,100 | 16,944 | 2,324* |
| Number of sites | 12 | 22 | Not specified | Not specified | 1 |
| Vaccine:control ratio | 2:1 | 2:1 | 1:1 | 2:1 | 1:1 |
| Power | 0.90 | 0.90 | - | - | 0.90 |
| Control | Placebo | Placebo | Placebo | Placebo | Placebo |
| Target efficacy | 0.70 | - | - | 0.80 | 0.80 |
| Lower bound of vaccine efficacy | 0.25 | 0.25 | - | 0.25 | 0.30 |
| Age groups | 2–5,6–11, 12–14 | 9–11, 12–16 | 4–16 | 2–6, 7–17,18–59 | 5–17, 18–45 |
| Primary endpoint | Symptomatic virologically-confirmed dengue disease | Symptomatic virologically-confirmed dengue disease | Symptomatic virologically-confirmed dengue disease | Symptomatic virologically-confirmed dengue disease | Symptomatic virologically-confirmed dengue disease |
| Vaccination schedule | Months: 0, 6, 12 | Months: 0, 6, 12 | Days: 1, 90 | Day 1 | Days: 1, 60 |
| Expected cases | 57 | 57 | 120 | 24 | 68 |
| Minimum timeframe to estimate VE | 1 year | 1 year | 1 year | 1 year | 1 year |
| Statistical analysis | Incidence density | Incidence density | Survival analysis | Incidence density | Survival analysis |
| Safety follow-up | 5 years | 5 years | 4.75 years | 5 years | - |
| Test for baseline DENV serology | Subset | Subset | Yes | - | Yes |
*Baseline scenario