Table 2.
Efficacy of Quadrivalent Vaccine Efficacy against External Genital Lesions in the Per-Protocol Population.*
| Variable | Quadrivalent HPV Vaccine | Placebo | Observed Efficacy | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| No. of Subjects | Cases of EGL no. |
Person-Yr at Risk | Rate no./100 person-yr at risk |
No. of Subjects | Cases of EGL no. |
Person-Yr at Risk | Rate no./100 person-yr at risk |
% (95% CI) | P Value† | |
| HPV type | ||||||||||
| Any type‡ | 1275 | 6 | 3172.9 | 0.20 | 1270 | 36 | 3081.1 | 1.20 | 83.8 (61.2 to 94.4) | |
| Type 6, 11, 16, or 18§ | 1397 | 3 | 2830.9 | 0.11 | 1408 | 31 | 2812.2 | 1.10 | 90.4 (69.2 to 98.1) | <0.001 |
| Type 6 | 1245 | 3 | 2562.3 | 0.12 | 1244 | 19 | 2553.8 | 0.74 | 84.3 (46.5 to 97.0) | |
| Type 11 | 1245 | 1 | 2563.7 | 0.04 | 1244 | 11 | 2552.6 | 0.43 | 90.9 (37.7 to 99.8) | |
| Type 16 | 1295 | 0 | 2644.0 | 0.00 | 1271 | 2 | 2586.2 | 0.08 | 100 (−420.8 to 100) | |
| Type 18 | 1335 | 0 | 2723.3 | 0.00 | 1354 | 1 | 2726.6 | 0.04 | 100 (−3804.6 to 100) | |
| Sexual orientation | ||||||||||
| Heterosexual males | 1200 | 2 | 2594.1 | 0.08 | 1198 | 26 | 2563.3 | 1.01 | 92.4 (69.6 to 99.1) | |
| Males who had sex with male partners | 197 | 1 | 236.8 | 0.42 | 210 | 5 | 248.9 | 2.01 | 79.0 (−87.9 to 99.6) | |
| Lesion type | ||||||||||
| Condyloma acuminatum | 1397 | 3 | 2830.9 | 0.11 | 1408 | 28 | 2813.9 | 1.00 | 89.4 (65.5 to 97.9) | |
| All PIN lesions | 1397 | 0 | 2833.3 | 0.00 | 1408 | 3 | 2824.5 | 0.11 | 100 (−141.2 to 100) | |
| PIN grade 1 | 1397 | 0 | 2833.3 | 0.00 | 1408 | 2 | 2826.0 | 0.07 | 100 (−431.1 to 100) | |
| PIN grade 2 or 3 | 1397 | 0 | 2833.3 | 0.00 | 1408 | 1 | 2824.7 | 0.04 | 100 (−3788.2 to 100) | |
| Penile, perianal, or perineal cancer | 1397 | 0 | 2833.3 | 0.00 | 1408 | 0 | 2826.2 | 0.00 | — | |
Data are shown for subjects who had at least one follow-up visit after month 7. EGL denotes external genital lesions with a diagnosis of condyloma acuminatum; HPV, human papillomavirus; and PIN, penile, perianal, or perineal intraepithelial neoplasia.
A P value of less than 0.025 (one-sided) corresponds to a lower bound of the confidence interval for vaccine efficacy of more than 20% and supports the conclusion that the vaccine is efficacious against the given end point.
For analysis of vaccine efficacy against any tested HPV type, subjects had negative results for DNA from HPV types 6, 11, 16, 18, 31, 33, 35, 39, 41, 51, 52, 56, 58, and 59 at enrollment and were seronegative to HPV types 6, 11, 16, and 18 at enrollment. Data are shown for subjects who had at least one follow-up visit after day 1. Analyses were conducted in accordance with the protocol.
Subjects were counted once in each applicable category. A subject may have been included in more than one category.