Safety of and Immune Response to an HIV Preventive Vaccine (HIV-1 Gag DNA Alone or With IL-15 DNA) Given With or Without 2 Different Booster Vaccinations in HIV Uninfected Adults

Note: Group 6 has been removed from Part B of the protocol as of the 04/11/06 amendment. Because a regimen similar to Group 6's regimen is being tested in HVTN 060, the vaccine manufacturer decided that Group 6's regimen was not a priority for testing. Inclusion Criteria: * HIV uninfected * Access to a participating HIV Vaccine Trials Unit (HVTU) * Willing to receive HIV test results * Willing and able to comply with all study requirements * In good general health * Willing to use acceptable methods of contraception for at least 21 days prior to study entry and until the last study visit. More information about this criterion can be found in the protocol. * Hepatitis B surface antigen negative * Anti-hepatitis C virus (anti-HCV) antibody negative or negative HCV PCR if anti-HCV antibody is positive Exclusion Criteria: * HIV vaccines in prior HIV vaccine trial * Immunosuppressive medications within 168 days prior to first vaccination * Blood products within 120 days prior to first vaccination * Immunoglobulin within 60 days prior to first vaccination * Live attenuated vaccines within 30 days prior to first vaccination * Investigational research agents within 30 days prior to first vaccination * Medically indicated subunit or killed vaccines within 14 days prior to first study vaccine administration, or allergy treatment with antigen injections within 30 days prior to first vaccination * Current tuberculosis (TB) prophylaxis or therapy * Clinically significant medical condition, physical exam findings, abnormal laboratory results, or past medical history with clinically significant implications for current health * Any medical, psychiatric, or social condition that, in the opinion of the investigator, may interfere with the study * Any occupational or other responsibility that, in the opinion of the investigator, may interfere with the study * Diagnosis of allergy to amide-type local anesthetics * Serious adverse reaction to vaccines, including anaphylaxis and related symptoms such as hives, respiratory difficulty, angioedema, or abdominal pain. A person who had an adverse reaction to pertussis vaccine as a child is not excluded. * Autoimmune disease or immunodeficiency * Unstable asthma * Diabetes mellitus Type 1 or Type 2. Participants with histories of isolated gestational diabetes are not excluded. * Thyroid disease requiring treatment in the past 12 months * Serious angioedema within the last 3 years * Uncontrolled hypertension * Body mass index (BMI) of 40 or greater OR BMI of 35 or greater, when certain other criteria are met. More information about these criteria can be found in the protocol. * Bleeding disorder * Cancer. Participants with surgically removed cancer that, in the opinion of the investigator, is unlikely to recur are not excluded. * Seizure disorder requiring medication within the past 3 years * Absence of the spleen * Psychiatric condition, including psychoses within the past 3 years, ongoing risk for suicide, or history of suicide attempt or gesture within the past 3 years * Pregnant or breastfeeding, or plan to become pregnant during the study Exclusion Criteria for Part B Participants: * Diagnosis of allergy to egg products * Diagnosis of allergy to yeast-derived products