Primary Objectives
1. Compared rates of seroconversion and geometric mean titers (GMTs) generated following a 3-dose series of vaccine in women given low doses of vaccine by the intradermal (ID) route with the needle-free injector (NFI) (Group III) to those women given standard doses by the intramuscular (IM) route with a needle and syringe (Group I) at 1 month, 6 months and 12 months following completion of the vaccination series.
2. Compared rates of seroconversion and GMTs generated following a 3-dose series of vaccine in women given standard doses of vaccine by the IM route with the NFI (Group II) to those women given standard doses by the IM route with a needle and syringe (Group I) at 1 month, 6 months and 12 months following completion of the vaccination series.
Serum samples were collected on 4 successive occasions: (1) day zero, prior to the first immunization, (2) at visit 4, one month following the third and final immunization, (3) at visit 5 (12 months) and (4) and at visit 6 (24 months after enrollment). Samples were split, stored and transferred in batch for analysis.
Merck received samples for processing and determined the geometric mean titer of antibodies specific to HPV (types 6, 11, 16, and 18) and results were transferred to the principal investigator. The University of California, San Francisco (UCSF) used a portion of the collected blood samples for pseudovirion-based neutralisation assay (PBNA) analysis conducted at UCSF.
