Additional Study Information: We are looking for healthy, HIV-negative individuals 18 to 50 years old who are interested in our studies that test antibodies for HIV prevention. Antibodies are one of the natural ways that our bodies fight or prevent infection. We are testing an antibody called VRC07-523LS against HIV. We will ask you to complete a brief questionnaire to find out if you are eligible. If you are eligible and decide to participate, you will come to clinic for 19 visits over little more than 2 years. You will receive an injection or infusion of the antibodies at five of these visits. You will be compensated $150 for the injection or infusion visits; $50 or $75 for visits involving blood draw and $25 for visits where no blood is drawn. Information learned from your participation will benefit science and HIV prevention.