 - Before randomization, a woman must be either; Not of childbearing potential: postmenopausal or surgically sterilized; of childbearing potential and practicing an effective method of birth control before vaccination and through 3 months after the last vaccination. Women, who are not heterosexually active at screening, must agree to utilize highly-effective method of birth control if they become heterosexually active until 3 months after receiving the last dose of study vaccine 