This study aimed to evaluate the efficacy of different hepatitis B vaccination regimens in HIV-infected adults with low CD4 cell count in northern Thailand.

HIV-infected adults with CD4+ cell counts < 200 cells/mm3, undetectable plasma HIV-1 RNA, and negative for all HBV markers were randomly assigned to receive one of these 2 regimens of recombinant hepatitis B vaccine (Centro De Ingenieria Genetica Y Biotecnologia, La Habana, Cuba); 1) 20 μg IM at months 0, 1, and 6 (3-standard doses group), and 2) 20 μg IM at months 0, 1, 2, 6 (4-standard doses group).

This study aimed to evaluate the efficacy and safety of these 2 hepatitis B vaccination regimens at month 7 after vaccination.

Inclusion Criteria:

1. HIV-infection
2. ≥18 years old
3. Received combination antiretroviral therapy for at least 1 year
4. Had a CD4+ cell count < 200 cells/mm3 for at least 1 year
5. Undetectable plasma HIV-1 RNA for at least 1 year
6. Negative for hepatitis B surface antigen (HBsAg), antibody to hepatitis B surface antigen (anti-HBs), and antibody to hepatitis B core antigen (anti-HBc),
7. Had no history of previous HBV vaccine
8. Negative for antibody to hepatitis C virus (anti-HCV)
9. No active opportunistic infections (at the time of screening)
10. Willing to sign an informed consent
11. Able to return for follow-up.

Exclusion criteria

1. Pregnancy or lactation
2. History of hypersensitivity to any component of the vaccine
3. Active malignancy receiving chemotherapy or radiation, or other immunocompromised conditions besides HIV (e.g., solid organ transplant), received immunosuppressive (e.g., corticosteroid ≥ 0.5 mg/kg/day) or immunomodulating treatment in the last six months before screening visit
4. Renal insufficiency (creatinine clearance <30 mL/min)
5. Decompensated cirrhosis (Child-Pugh class C)