Table 2. Characteristics of COVID-19 Vaccine Clinical Trials Considered by Medicine Regulators.
| Feature | Median (range) |
|---|---|
| Clinical trials supporting vaccine approval, No. | 4 (2-5) |
| Pivotal efficacy trials supporting vaccine approval, No. | 1 (1-2) |
| Clinical trial, No. (%) | |
| With randomization | 12 (85.7) |
| With double-masking | 9 (64.2) |
| With active comparatora | 3 (21.4) |
| With placebo comparator | 9 (64.2) |
| With primary clinical end point | 8 (57.1) |
| Patients in Phase 2/3 safety database, median (range), No. | |
| Total | 33 818 (12 021-43 783) |
| Receiving COVID-19 vaccine | 16 993 (12 021-21 895) |
| Receiving active/placebo comparator | 16 826 (11 724-21 888) |
a
All studies used the Meningococcal group A, C, W-135, and Y conjugate vaccine as an active comparator.