The purpose of the study is to determine the safety of and immune response to a hepatitis B virus vaccine series given with a boosting agent, CpG7909 oligodeoxynucleotides (ODN), in HIV infected and HIV uninfected individuals who previously failed to develop a response to hepatitis B vaccine.

Study hypothesis: Administration of CpG7909 ODN together with recombinant hepatitis B vaccine will result in increased frequency and magnitude of response to vaccine in individuals who have previously failed to mount a response to vaccination, and that in HIV infected subjects with detectable plasma viremia, it will lead to the enhancement of HIV-specific responses.

As HIV disease progresses in HIV infected people, their immune responses to infectious and other foreign invaders becomes weaker; in particular, the cellular (T-cell) immune response is particularly affected by HIV. A boosting agent called CpG7909 ODN may be an ideal adjuvant for vaccines given to HIV infected people, because it may help elicit an increased CD8 T-cell response. This study will evaluate the safety of and immune response to a hepatitis B virus vaccine series given with CpG7909 ODN in HIV infected and uninfected people.

There will be three groups in this study; participants will be stratified by baseline CD4 counts and viral load. Within each group, participants will be randomly assigned to receive 3 injections of hepatitis B vaccine with CpG7909 ODN or 3 injections of hepatitis B vaccine alone. Injections will be given at study entry and Months 1 and 6. There will be 10 study visits; a physical exam and blood collection will occur at each visit.

Inclusion Criteria for HIV Infected Participants:

• HIV-1 infection
• If receiving combination antiretroviral therapy (ART), must have been on ART for at least 3 months prior to study entry. Patients who anticipate a change in treatment (either initiating ART or stopping ART) in the next 7 months are not eligible.
• CD4 count of 250 cells/mm3 or greater
• Negative HBsAb, HBsAg, and HBcAb
• Willing to use acceptable forms of contraception while on study treatment and for 24 weeks after study treatment has ended

Inclusion Criteria for HIV Uninfected Participants:

• HIV uninfected
• Negative HBsAb, HBsAg, and HBcAb
• Willing to use acceptable forms of contraception while on study treatment and for 24 weeks after study treatment has ended

Exclusion Criteria for All Participants:

• Cancer. Participants with squamous cell or basal cell skin cancer are not excluded.
• Autoimmune disease
• Immunosuppressive medications. People who use or have used corticosteroid nasal sprays are not excluded. People who have received fewer than 2 weeks of systemic corticosteroids with the last dose over a month prior to study entry are not excluded.
• Any medical or psychiatric condition or occupational responsibilities that may interfere with the study
• Immunomodulator or investigational agent therapy within 30 days prior to study entry
• Allergy/sensitivity to study drugs or their formulations, including thimerosal
• Current drug or alcohol use that, in the opinion of the investigator, would interfere with the study
• Active hepatitis C virus infection, as indicated by serum antibodies to HCV AND detectable HCV RNA in plasma
• Blood clotting abnormalities
• Any other condition that, in the opinion of the investigator, might interfere with the study
• Pregnancy or breastfeeding