Table 2 Examples of total sample sizes required for field studies of second-generation vaccine to demonstrate non-inferiority or superiority (reported in 1,000s; assuming intention-to-treat)
From: MALVAC 2012 scientific forum: accelerating development of second-generation malaria vaccines
Power (1-β) | : 80% | ||
|---|---|---|---|
Two-sided significance level (α) | : 5% | ||
Control vaccine efficacy | : 50% | ||
Follow-up time | : 2 years | ||
Incidence rate in those not vaccinated | : 1/10 PYs | ||
New vaccine efficacy (%) | Superiority | Non-inferiority margin | |
| Â | Â | 5% | 10% |
50 | --- | 28.7 | 7.3 |
55 | 27.4 | 7.0 | 3.2 |
60 | 6.6 | 3.0 | 1.7 |
65 | 2.9 | 1.6 | 1.1 |