VRC 601: A Phase I, Open-Label, Dose-Escalation Study of the Safety and Pharmacokinetics of a Human Monoclonal Antibody, VRC HIVMAB060-00-AB (VRC01), With Broad HIV-1 Neutralizing Activity, Administered Intravenously or Subcutaneously to HIV-Infected...

* INCLUSION CRITERIA: A volunteer must meet all of the following criteria: 1. Able and willing to complete the informed consent process. 2. 18-60 years old during the dose escalation; 18-70 years old during subsequent enrollment of viremic subjects. 3. HIV infected and clinically stable,Volunteers during the dose escalation part of the study also must be, without changes in ARV status (whether or not taking an ARV regimen) in the 24 weeks prior to enrollment. 4. Criteria for volunteers enrolling during the dose escalation part of the study: Plasma viral load (VL) and CD4 count that meet eligibility criteria on at least two measurements performed within the 24 weeks prior to enrollment. The two measurements used for eligibility must have at least 3 days between tests and at least one set of the tests must be performed at the NIH Clinical Center within the 84 days prior to enrollment. If not on ARV treatment, the criteria are: -VL less than or equal to 50,000 copies/mL and a CD4 count greater than or equal to 400/mcL. If on ARV treatment, the criteria are: -VL less than or equal to 50 copies/mL and a CD4 count greater than or equal to 350/mcL. Note: A viral blip of \<400 copies/mL during the 24 weeks prior to enrollment is permitted if preceded and followed by test results showing VL less than or equal to 50 copies/mL on the same ARV regimen.\] Criteria for viremic volunteers enrolling after dose escalation is complete: At least one detectable plasma viral load greater than or equal to 50 copies/mL and at least one CD4 count greater than or equal to 200 cells/mcL within 84 days prior to enrollment. Note: Up to 10 viremic subjects will be enrolled but no more than 4 subjects with a screening VL \>100,000 copies/mL will receive VRC01. Other subjects must have a screening VL less than or equal to 100,000 copies/mL 5. In general good health and willing to maintain or establish a relationship with a primary health care provider for medical management of HIV infection while participating in the study. 6. Willing to have blood samples collected, stored indefinitely, and used for various research purposes. 7. Able to provide proof of identity to the satisfaction of the study clinician completing the enrollment process. 8. Screening laboratory values within 84 days prior to enrollment must meet the following criteria: * absolute neutrophil count greater than or equal to 800/mcL * platelets greater than or equal to 100,000/mcL * hemoglobin greater than or equal to 10.0 gm/dL * creatinine less than or equal to 1.31 mg/dL * alanine aminotransferase (ALT) less than or equal to 2.5 times ULN Female-Specific Criteria: 9. Agrees not to become pregnant from the time of study enrollment until the last study visit. If a woman is sexually active and has no history of hysterectomy or tubal ligation or menopause, she must agree to use a prescription birth control method or a barrier birth control method. 10. Negative Beta-HCG (human chorionic gonadotropin) pregnancy test (urine or serum) on day of enrollment for any women unless she is post-menopause for 24 consecutive months or has undergone a surgical procedure that precludes pregnancy. EXCLUSION CRITERIA: A volunteer will be excluded if one or more of the following conditions apply: 1. Previous receipt of humanized or human monoclonal antibody whether licensed or investigational. 2. Weight \>130 kg or \<53 kg. 3. Ongoing AIDS-related opportunistic infection (including oral thrush) 4. Active injection drug use or active drug or alcohol use or dependence that, in the opinion of the site investigator, would interfere with adherence to study requirements. 5. History of a severe allergic reaction with generalized urticaria, angioedema or anaphylaxis in the 2 years prior to enrollment. 6. Physical finding on examination considered clinically significant such as murmur (other than functional), hepatosplenomegaly, lymphadenopathy or focal neurological deficit. 7. Hypertension that is not well controlled by medication. 8. Breast-feeding. 9. Receipt of other investigational study agent within 28 days prior to enrollment. 10. Any other chronic or clinically significant medical condition that in the opinion of investigator would jeopardize the safety or rights of the volunteer.