 - If the participant is female, she must be of non-childbearing potential i.e., either pre-menarcheal, surgically sterilized, or one year post-menopausal, or, if of childbearing potential, she must be abstinent or have used adequate contraceptive precautions i.e., intrauterine contraceptive device, condom and spermicide combination, oral contraceptives or other equivalent hormonal contraception e.g., progestin implantable, cutaneous hormonal patch, or injectable contraceptives for 30 days prior to vaccination, have a negative pregnancy test prior to vaccination, and must agree to continue such precautions for 60 days after completion of the vaccination series. Any child who begins menarche during the study period must follow the same precautions listed above, from menarche until 60 days after the second vaccine dose. 