Table 1.

Baseline characteristics of participants in the study population (protocols 007, 013, and 015)

Baseline characteristicQuadrivalent HPV vaccine (N = 9,087)Placebo (N = 9,087)
Age (y)
    Mean ± SD20.0 ± 2.020.0 ± 2.0
    Median (range)20 (15-26)20 (13-26)
Race, m/n (%)
    Asian309/9,087 (3.4%)311/9,087 (3.4%)
    Black332/9,087 (3.7%)412/9,087 (4.5%)
    Hispanic American1,136/9,087 (12.5%)1,143/9,087 (12.6%)
    Native American13/9,087 (0.1%)12/9,087 (0.1%)
    White6,400/9,087 (70.4%)6,322/9,087 (69.6%)
    Other897/9,087 (9.9%)887/9,087 (9.8%)
Lifetime number of sex partners at enrollment, m/n (%)
    0 (Virgin)517/9,087 (5.7%)561/9,087 (6.2%)
    12,929/9,087 (32.2%)2,938/9,087 (32.3%)
    22,210/9,087 (24.3%)2,224/9,087 (24.5%)
    31,798/9,087 (19.8%)1,754/9,087 (19.3%)
    41,519/9,087 (16.7%)1,477/9,087 (16.3%)
    >4111/9,087 (1.2%)128/9,087 (1.4%)
    Unknown3/9,087 (0.0%)5/9,087 (0.1%)
New sex partners in 6 mo before study start,* m/n (%)
    05,990/8,570 (69.9%)5,881/8,526 (69.0%)
    12,196/8,570 (25.6%)2,231/8,526 (26.2%)
    2307/8,570 (3.6%)317/8,526 (3.7%)
    350/8,570 (0.6%)64/8,526 (0.8%)
    412/8,570 (0.1%)16/8,526 (0.2%)
    >411/8,570 (0.1%)13/8,526 (0.2%)
    Unknown4/8,570 (0.0%)4/8,526 (0.0%)
Prevalence of sexually transmitted disease, m/n (%)
    Chlamydia379/8,939 (4.2%)367/8,915 (4.1%)
    Gonorrhea35/6,764 (0.5%)23/6,742 (0.3%)
Pregnancy history, m/n (%)
    With history of pregnancy2,057/9,087 (22.6%)2,041/9,087 (22.5%)
Day 1 Pap status, m/n (%)
    ASC-US or worse before study or on day 11,003/8,691 (11.5%)986/8,658 (11.4%)
    ASC-US or worse with positive high-risk HPV probe47/8,691 (0.5%)66/8,658 (0.8%)
HPV positivity at day 1
PCR positive, m/n (%)
    Positive to HPV 6/11/16/181,329/8,983 (14.8%)1,317/8,997 (14.6%)
    Positive to HPV 6372/8,962 (4.2%)348/8,977 (3.9%)
    Positive to HPV 1166/8,978 (0.7%)55/8,992 (0.6%)
    Positive to HPV 16781/8,932 (8.7%)783/8,967 (8.7%)
    Positive to HPV 18317/8,969 (3.5%)323/8,986 (3.6%)
Seropositive, m/n (%)
    Positive to HPV 6/11/16/181,792/9,067 (19.8%)1,788/9,066 (19.7%)
    Positive to HPV 6738/9,067 (8.1%)745/9,066 (8.2%)
    Positive to HPV 11189/9,066 (2.1%)187/9,066 (2.1%)
    Positive to HPV 161,001/9,067 (11.0%)1,037/9,066 (11.4%)
    Positive to HPV 18332/9,066 (3.7%)338/9,066 (3.7%)
PCR positive and/or seropositive
    Positive to HPV 6/11/16/182,434/9,074 (26.8%)2,418/9,074 (26.6%)
    Positive to HPV 6962/9,074 (10.6%)962/9,074 (10.6%)
    Positive to HPV 11231/9,074 (2.5%)223/9,074 (2.5%)
    Positive to HPV 161,433/9,074 (15.8%)1,445/9,074 (15.9%)
    Positive to HPV 18574/9,074 (6.3%)572/9,074 (6.3%)

NOTE: N is the number of subjects randomized to the respective vaccination group; n is the number of subjects with nonmissing day 1 result with respect to the relevant method assessment of the given characteristic; and m is the number of subjects who were positive at day 1 with respect to the relevant method assessment of the given characteristic.

Abbreviation: ASC-US, atypical squamous cells of undetermined significance.

  • *Among nonvirgins.