Table 1 Demographic and clinical characteristics of study participants.
| Â | Vaccine N = 3783 | Placebo N = 3828 |
|---|---|---|
Mean age, years (SD) | 32.7 (9.19) | 32.7 (9.14) |
1. Male, n (%) | 1465 (39) | 1520 (40) |
Age stratum, n (%) | Â | Â |
   Age 18 - 34 | 2153 (57) | 2181 (57) |
   Age 35 - 49 | 1630 (43) | 1647 (43) |
Race, n (%) | Â | Â |
   Caucasian | 3166 (84) | 3237 (85) |
   Black or African American | 384 (10) | 362 (9) |
   Asian | 61 (2) | 75 (2) |
   Native Hawaiian or Pacific Islander | 10 (<1) | 15 (<1) |
   Native American/Alaskan Native | 18 (<1) | 9 (<1) |
   Other | 144 (4) | 129 (3) |
Received Prior Vaccination (≤ 2 years), n (%) | 727 (19) | 727 (19) |