For persons living with HIV (PLWH), a three-dose hepatitis B virus (HBV) vaccine adjuvanted to a TLR-9 agonist (HepB-CpG) yields 100% Sero protection, according to a study presented at IDWeek. Kristen Marks, MD, and colleagues examined the immunogenicity of the HBV vaccine HepB-CpG in PLWH. A total of 74 eligible participants without past HBV infection who had CD4 counts of 100 cells/mm3 or greater and HIV-1 RNA of less than 1,000 copies/mL received HepB-CpG at weeks 0, 4, and 24. The primary analysis included 68 participants. All participants completed three doses and achieved Sero protection (anti-HepB virus surface antibodies [HBsAb], ≥10 mIU/mL). Overall, 88% had HBsAb greater than 1,000 mIU/mL. In the per-protocol analysis including 62 participants, the Sero protection rate (SPR) was 100%. At 8 weeks after the second dose and at week 24 before the third dose, the SPRs were 94.4% and 98.5%, respectively. The proportion of participants with HBsAb of greater than 1,000 mIU/ mL increased from 27.9% at week 24 to 83.8% at week 28. “No unexpected safety issues were observed,” Dr. Marks and colleagues wrote.