 - Women of reproductive potential defined as being 1 year post-menopausal must have a negative serum B human chorionic gonadotropin bHCG pregnancy test within 3 days prior to study entry; and men and women of reproductive potential must agree to practice an effective method of avoiding pregnancy including oral or implanted contraceptives, intrauterine device IUD, condom, diaphragm with spermicide, cervical cap, abstinence, or sterile sexual partner at the time informed consent is signed women only or at the time of the initiation of MEDI-522 men only, and must agree to continue using such precautions while receiving MEDI-522 and for 30 days after the final dose of MEDI-522 