Safety and Pharmacokinetics of a Human Monoclonal Antibody, VRC-HIVMAB080-00-AB (VRC01LS), With Broad HIV-1 Neutralizing Activity, Administered Intravenously or Subcutaneously to Healthy Adults

Background: Antibodies help the body fight infection. VRC01LS is an antibody directed against HIV virus. HIV attacks the immune system. In animals, VRC01LS inactivated many types of HIV viruses. Researchers want to see if it does this in people. Objectives: To see if VRC01LS is safe and well-tolerated in people. To see what level of VRC01LS is maintained in people and if they develop an immune response to it. Eligibility: Healthy people ages 18 to 50 Design: Participants will be screened in protocol number VRC 500 (NIH 11-I-0164) with medical history, physical exam, and blood and urine tests. The study will last 24 to 48 weeks. Visits will last 2 to 8 hours. Participants will get VRC01LS through either: * A needle in an arm vein or * A small needle placed into the fatty tissue under the skin of the abdomen, thigh, or arm. Participants will be assigned to 1 of 6 groups. Groups 1 to 4 will get 1 dose of VRC01LS. They will have follow-up visits through week 24. Groups 5 and 6 will get 1 dose of VRC01LS every 12 weeks (3 doses). They will have 4 to 5 visits between the second and third dose, and follow-up visits through week 48. Participants will have 1 to 3 follow-up visits in the week after receiving VRC01LS. They will record their temperature and keep a diary of symptoms for 3 days after a dose. They may have additional unscheduled visits. At each visit, participants will have a physical exam and may have blood and urine tests.