V503 (9-valent HPV [Types 6, 11, 16, 18, 31, 33, 45, 52, and 58] L1 virus-like particle vaccine), 0.5 mL injection in 3 dose regimen (and a fourth injection for Cohort 1 only).

An AE is defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally associated with the use of the study vaccine, whether or not considered related to the use of the product. Any worsening of a preexisting condition which is temporally associated with the use of the study vaccine is also an AE. AEs such as redness, swelling, and pain/tenderness/soreness at the injection site were recorded.

An AE is defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally associated with the use of the study vaccine, whether or not considered related to the use of the product. Any worsening of a preexisting condition which is temporally associated with the use of the study vaccine is also an AE. Systemic AEs were those not categorized as injection-site AEs.

An AE is defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally associated with the use of the study vaccine, whether or not considered related to the use of the product. Any worsening of a preexisting condition which is temporally associated with the use of the study vaccine is also an AE. An AE that is judged by the investigator to be "definitely related," "probably related," or "possibly related" to the study drug is defined as a vaccine-related AE.

An adverse event is defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally associated with the use of the study vaccine, whether or not considered related to the use of the product. Any worsening of a preexisting condition which is temporally associated with the use of the study vaccine is also an adverse event.

Serum antibodies to HPV types were measured with a Competitive Luminex Immunoassay. The serostatus cutoffs (milli Merck U/mL) for HPV types were as follows: HPV Type 6: ≥30; HPV Type 11: ≥16; HPV Type 16: ≥20; HPV Type 18: ≥24; HPV Type 31: ≥10; HPV Types 33, 45, 52, and 58: ≥8.

Serum antibodies to HPV types 6/11/16/18/31/33/45/52/58 were measured with a Competitive Luminex Immunoassay. Titers are reported in milli Merck Units/mL. This outcome measure applied to Cohort 1 participants only.

Serum antibodies to HPV types 6/11/16/18/31/33/45/52/58 were measured with a Competitive Luminex Immunoassay. Titers are reported in milli Merck Units/mL. This outcome measure applied to Cohort 1 participants only.

V503 (9-Valent HPV Vaccine) high-dose 0.5 mL injection in a 3-dose regimen in the base study.

Gardasil (4-Valent HPV Vaccine) 0.5 mL injection in a 3-dose regimen in the base study. Participants (Cohort 2) were offered the V503 mid-dose 3-dose regimen in the extension study.

Total of all reporting groups

HPV Type 31/33/45/52/58-related high-grade Cervical Intraepithelial Neoplasia (CIN 2/3), Adenocarcinoma in Situ (AIS), Invasive Cervical Carcinoma, high-grade Vulvar Intraepithelial Neoplasia (VIN 2/3), high-grade Vaginal Intraepithelial Neoplasia (VaIN 2/3), vulvar cancer, or vaginal cancer were determined by clinical/pathologic criteria and positive Polymerase Chain Reaction (PCR) assay for virus subtype. This outcome measure reports cumulative study data through 10 March 2014. Disease incidence was defined as the number of primary efficacy cases per 10,000 person-years of follow-up in a treatment arm.

The Per-protocol Efficacy population included all participants who received all 3 vaccinations of mid-dose V503 or Gardasil within acceptable day ranges, were seronegative at Day 1 and PCR negative at Day 1 through Day 7 to the relevant HPV types, and had at least 1 follow-up visit following Month 7.

Serum antibodies to HPV types 6/11/16/18/31/33/45/52/58 were measured with a Competitive Luminex Immunoassay. Titers are reported in milli Merck Units/mL. Statistical analysis was performed only for HPV types contained in both vaccines.

The Per-protocol Immunogenicity population included all participants who were not protocol violators, received all 3 vaccinations of mid-dose V503 or Gardasil within acceptable ranges, were seronegative at Day 1 and PCR negative from Day 1- Month 7 for the relevant HPV types, and had a Month 7 serum sample collected within an acceptable range

Serum antibodies to HPV types 6/11/16/18/31/33/45/52/58 were measured with a Competitive Luminex Immunoassay. Titers are reported in milli Merck Units/mL. This outcome measure applied to Cohort 1 participants only.

All participants in Cohort 1 who received all 3 vaccinations of mid-dose V503 in the Base Study, were seronegative at Day 1 and PCR negative from Day 1 to Month 7 for the relevant HPV types, had no other violation that could interfere with evaluation of immune response, and provided post-dose 4 serum.

An AE is defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally associated with the use of the study vaccine, whether or not considered related to the use of the product. Any worsening of a preexisting condition which is temporally associated with the use of the study vaccine is also an AE.

The analysis population included all participants who received >=1 vaccination and had safety follow-up

An AE is defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally associated with the use of the study vaccine, whether or not considered related to the use of the product. Any worsening of a preexisting condition which is temporally associated with the use of the study vaccine is also an AE. AEs such as redness, swelling, and pain/tenderness/soreness at the injection site were recorded.

The analysis population included all participants who received >=1 vaccination and had safety follow-up

An AE is defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally associated with the use of the study vaccine, whether or not considered related to the use of the product. Any worsening of a preexisting condition which is temporally associated with the use of the study vaccine is also an AE. Systemic AEs were those not categorized as injection-site AEs.

The analysis population included all participants who received >=1 vaccination and had safety follow-up

An AE is defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally associated with the use of the study vaccine, whether or not considered related to the use of the product. Any worsening of a preexisting condition which is temporally associated with the use of the study vaccine is also an AE. An AE that is judged by the investigator to be "definitely related," "probably related," or "possibly related" to the study drug is defined as a vaccine-related AE.

The analysis population included all participants who received >=1 vaccination and had safety follow-up

An adverse event is defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally associated with the use of the study vaccine, whether or not considered related to the use of the product. Any worsening of a preexisting condition which is temporally associated with the use of the study vaccine is also an adverse event.

The analysis population included all participants who received >=1 vaccination and had safety follow-up

Combined Incidence of HPV Type 31/33/45/52/58-related persistent infection as determined by clinical/pathologic criteria and positive Polymerase Chain Reaction (PCR) assay for virus subtype. Persistent infection was defined as infection detected in samples from >=2 consecutive visits 6 months (+/-1 month visit window) or longer apart. Incidence was defined as the number of cases of persistent infection per 10,000 person-years of follow-up in a treatment arm.

The Per-protocol Efficacy population included all participants who received all 3 vaccinations of mid-dose V503 or Gardasil within acceptable day ranges, were seronegative at Day 1 and PCR negative at Day 1 through Day 7 to the relevant HPV types, and had at least 1 follow-up visit following Month 7.

Serum antibodies to HPV types were measured with a Competitive Luminex Immunoassay. The serostatus cutoffs (milli Merck U/mL) for HPV types were as follows: HPV Type 6: ≥30; HPV Type 11: ≥16; HPV Type 16: ≥20; HPV Type 18: ≥24; HPV Type 31: ≥10; HPV Types 33, 45, 52, and 58: ≥8.

The Per-protocol Immunogenicity population included all participants who were not protocol violators, received all 3 vaccinations of mid-dose V503 or Gardasil within acceptable ranges, were seronegative at Day 1 and PCR negative from Day 1 - Month 7 for the relevant HPV types, and had a Month 7 serum sample collected within an acceptable range

Serum antibodies to HPV types 6/11/16/18/31/33/45/52/58 were measured with a Competitive Luminex Immunoassay. Titers are reported in milli Merck Units/mL. This outcome measure applied to Cohort 1 participants only.

All participants in Cohort 1 who received all 3 vaccinations of mid-dose V503 in the Base Study, were seronegative at Day 1 and PCR negative from Day 1 to Month 7 for the relevant HPV types, had no other violation that could interfere with evaluation of immune response, and provided post-dose 4 serum.

Serum antibodies to HPV types 6/11/16/18/31/33/45/52/58 were measured with a Competitive Luminex Immunoassay. Titers are reported in milli Merck Units/mL. This outcome measure applied to Cohort 1 participants only.

All participants in Cohort 1 who received all 3 vaccinations of mid-dose V503 in the Base Study, were seronegative at Day 1 and PCR negative from Day 1 to Month 7 for the relevant HPV types, had no other violation that could interfere with evaluation of immune response, and provided post-dose 4 serum.

V503 (9-Valent HPV Vaccine) mid-dose 0.5 mL injection in a 3-dose regimen in the base study. A subset of participants (Cohort 1) will receive a fourth V503 mid-dose vaccination in the extension study.

V503 (9-Valent HPV Vaccine) high-dose 0.5 mL injection in a 3-dose regimen in the base study.

Gardasil (4-Valent HPV Vaccine) 0.5 mL injection in a 3-dose regimen in the base study. Participants (Cohort 2) will be offered the V503 mid-dose 3-dose regimen in the extension study.

V503 (9-Valent HPV Vaccine) mid-dose 0.5 mL fourth dose administration in Base Study participants who were randomized to receive a 3-dose regimen of V503 (9-Valent HPV) mid-dose 0.5 mL (Cohort 1).

V503 (9-Valent HPV Vaccine) mid-dose 0.5 mL 3-dose regimen administration on Base Study participants who were randomized to receive a 3-dose regimen of Gardasil (4-Valent HPV Vaccine) (Cohort 2).