V710 First-In-Man (FIM) Study (V710-001)

This is a randomized, Multicenter, double-blind (subject, investigator, and Merck Research Laboratories (MRL) clinical personnel directly involved in the study), placebo-controlled, dose-ranging study in healthy adults 18 to 55 years of age. It is the first in man (FIM) study evaluating the tolerability and immunogenicity of the 0657nI S. aureus vaccine. For this Phase I study, approximately 120 healthy adults will be enrolled in the study and randomized to receive a single 0.5 mL vaccination of either 0657nI S. aureus vaccine (3 different dosage levels of 5 μg, 30 μg or 90 μg of the 0657nI vaccine) or saline placebo. Vaccine/placebo will be administered intramuscularly (IM) in the deltoid muscle. Because this study will be the first study evaluating the tolerability and immunogenicity of 0657nI S. aureus vaccine in humans, a dose-escalation phase will be conducted in a small number of subjects randomized in a 3:1 ratio (n=36, consisting of 9 subjects for each of 3 vaccine dosage levels and 9 placebo subjects) to evaluate the vaccine safety at increasing dose levels of the 0657nI protein in Panel A, before expanding the enrollment to the remaining 84 subjects in Panel B.