HIV Vaccine Trial in Thai Adults

Inclusion Criteria: * Possession of the 13-digit Thai National ID card * 18-30 years of age (inclusive), male or female * For women, a negative urine pregnancy test on the day of enrollment, as well as assurance that adequate birth control measures would be applied during the course of the injections and the 3 months after the last injection. * Absence of systemic disease or immunodeficiency as determined by medical history and directed physical examination. * Negative serology for HIV-1 infection within 45 days prior to enrollment. * Availability and commitment for 3.5 years of participation. * Able to understand the study (shown by receiving a passing score on the Test of Understanding administered under the screening protocol) and gave written informed consent. * Enrollment in and referral from screening protocol, RV148 Exclusion Criteria: * Previous participation in any HIV vaccine trial (unless the volunteer could provide documentation that he/she received placebo). * Active tuberculosis, other systemic disease process, or immunodeficiency as detected by medical history and directed physical examination that would, in the opinion of the investigator, impede compliance with study requirements or complicate the interpretation of adverse events. * Any significant finding that in the opinion of the investigator would increase the risk of having an adverse outcome from participating in this study or might interfere with the volunteer's ability to successfully complete the study. * Occupational or other responsibilities that would prevent completion of 3.5 years of participation in the study. * History of anaphylaxis or other serious adverse reactions to vaccines, or allergies or reactions likely to be exacerbated by any component of the vaccine or placebo, including egg products and neomycin. * Women breast-feeding or pregnant (positive pregnancy test) or planning to become pregnant during the 9-month window between study enrollment and 3-months after the last vaccination visit. * Study site employees who were involved in the protocol and may have had direct access to trial-related data. * Chronic use of therapies which may modify immune response, such as IV immune globulin and systemic corticosteroids (in doses of \> 20 mg prednisone equivalent for periods exceeding 10 days), and use of experimental drugs or vaccines. * Receipt of a non-HIV vaccine or immune globulins within 14 days.