Table 2.
Limits on Vaccine Efficacy (High) and Vaccine Efficacy (Low) When Power Achieves 80% at Different Splits in Percentages in the Low Vaccine Efficacy and High Vaccine Efficacy Subgroupsa
| No. of Cases = 10; No. of Controls = 50 | No. of Cases = 20; No. of Controls = 100 | ||||
|---|---|---|---|---|---|
| % With Low VE | % With High VE | Min VE(High)% | Max VE(Low)% | Min VE(High)% | Max VE(Low)% |
| 10 | 40 | –b | –b | >94 | <9 |
| 15 | 50 | >95 | 0 | >90 | <24 |
| 15 | 60 | >95 | <5 | >89 | <26 |
| 20 | 70 | >93 | <13 | >87 | <34 |
Abbreviation: VE, vaccine efficacy.
a Overall VE = 75%; precision 
= 0.9.
b Does not achieve 80% power for any VE(High) and VE(Low).