Group^{b} | Vaccine | No. of subjects overall | No. of subjects contributing to the analysis | Noninferiority by: | |
---|---|---|---|---|---|

GMT (mMU/ml)^{c} | Seroconversion (%)^{d} | ||||

A | Quadrivalent | 1,783 | 1,047 | 2,030.4 | 99.8 |

B | Monovalent | 304 | 181 | 1,911.0 | 100.0 |

↵

*a*The per-protocol immunogenicity population included all subjects who were not general protocol violators, received all three vaccinations within acceptable day ranges, were seronegative for the relevant HPV type(s) at day 1 and PCR negative from day 1 through month 7, and had a month 7 serum sample collected within an acceptable day range.↵

*b*Subjects who received at least one injection were randomized to the quadrivalent and monovalent vaccination groups.↵

*c*The estimated difference (*n*-fold) between the GMTs of groups A and B was 1.06 (95% confidence interval, 0.84 to 1.35). The*P*value for noninferiority was <0.001. For the null hypothesis that the ratio of the group A GMT to the group B GMT is ≤0.5, a*P*value of <0.025 supported a conclusion that the anti-HPV16 response in the quadrivalent HPV (types 6, 11, 16, and 18) L1 VLP vaccine group was noninferior to the response in the monovalent HPV16 L1 VLP vaccine group. The estimated GMT, difference (*n*-fold), associated confidence intervals, and*P*values were based on a statistical analysis model adjusting for country.↵

*d*The estimated percentage point difference between group A and B seroconversion rates was −0.02 (95% confidence interval, −0.7 to 2.0). The*P*value for noninferiority was <0.001. For the null hypothesis that the percentage of group A seroconverters minus the percentage of group B seroconverters is ≤−0.05, a*P*value of <0.025 supported a conclusion that the anti-HPV16 seroconversion rate in the quadrivalent HPV (types 6, 11, 16, and 18) L1 VLP vaccine group was noninferior to that in the monovalent HPV16 L1 VLP vaccine group.