Determining Responses to Two Different Vaccines in HIV and HCV Infected Individuals

Inclusion Criteria for Arm A Participants: * HCV-infected * HIV-uninfected Inclusion Criteria for Arm B Participants: * HIV-infected * HCV-uninfected * CD4 count greater than or equal to 300 cells/mm3 within 60 days prior to study entry Inclusion Criteria for Arm C Participants: * HIV-infected * HCV-infected Inclusion Criteria for All Participants: * Documented hepatitis B virus (HBV) antibody status. If anti-HBV core antibody positive, documented HBV negative test within 30 days prior to study entry is required. * Willing to use acceptable forms of contraception for the duration of the study and for 24 weeks after the last vaccination Exclusion Criteria for Arm A Participants: * Concurrent or recent treatment for HCV infection (within the past three months) Exclusion Criteria for Arm B Participants: * Current, prior, or clinical need for antiretroviral therapy (within the past three months prior to study entry) * Opportunistic infection other than HCV Exclusion Criteria for Arm C Participants: * Concurrent or recent treatment for HCV infection (within the past three months) * Current, prior, or clinical need for antiretroviral therapy (within the past three months prior to study entry). More information on this criterion can be found in the protocol. * Opportunistic infection other than HCV Exclusion Criteria for All Participants: * History of exposure to hepatitis A vaccine, hepatitis B vaccine, or combined hepatitis A-hepatitis B vaccines * Immunomodulatory agents for 7 days or more within 30 days prior to study entry. More information on this criterion can be found in the protocol. * Concurrent immunizations (e.g., influenza, pneumococcal, other vaccine)within 3 days prior to study entry * Active or recent (in the last six months prior to study entry) CDC Category C event. More information on this criterion can be found in the protocol * Systemic anticancer chemotherapy or radiation within 24 weeks prior to study entry, or anticipated need to begin such treatment * Past or current immunologically-mediated disease. More information on this criterion can be found in the protocol. * Current bacterial infection requiring treatment, therapy, or hospitalization within 1 week prior to study entry * Serious illness requiring systemic treatment and/or hospitalization. Participants who complete therapy or are clinically stable on therapy for at least 14 days prior to study entry are not excluded. * Current uncontrolled seizure disorders * Active bleeding varices, or Child's B or C cirrhosis. More information on this criterion can be found in the protocol. * Serious bleeding disorder that poses a risk to a participant for intramuscular injections * Known allergy or sensitivity to study vaccines or their formulations * Current drug or alcohol use that, in the opinion of the investigator, interferes with study participation * Pregnant or breastfeeding * Use of systemic investigational agents within 30 days prior to entry * History of any hepatitis A vaccine within one year