21. Current and Nadir CD4+ Counts Are Associated with Heplisav-B Seroprotection Rates in People with HIV

Abstract

Background: A two‐dose hepatitis B (HBV) vaccine with an immunostimulatory adjuvant (HBV‐ISS, Heplisav‐B), was FDA approved in 2017 for adults 18 years and older. In randomized controlled trials (RCTs), HBV‐ISS demonstrated a seroprotection rate (SPR) of 90‐95% versus 65‐80% for Engerix‐B (HBV‐Eng). No RCTs, however, included people with HIV (PWH), and the SPR and its predictors in this population are unknown. Methods: This retrospective cohort study enrolled PWH ages 18 years and older without current HBV seroprotection at an HIV clinic at a tertiary care center. HBV seroprotection was defined as an anti‐HBV surface antibody level >= 10 mIU/mL. Patients without follow‐up titers after immunization were excluded. The primary outcome was the SPR, the proportion of patients with HBV seroprotection at any point following the first HBV‐ISS vaccination. Results: Among the 51 PWH included, 50 received 2 doses of HBV‐ISS (1 patient who received 1 dose developed seroprotection) (Table 1). Median time to antibody titer measurement was 11 weeks (IQR 7‐19 weeks). Median age was 59 years, 90% were men, and 96% had VL < 200. There were no pregnant or breastfeeding patients. The SPR was 82% (42/51) in the cohort, and 86% (38/44) when patients with significant non‐HIV immunosuppression (decompensated cirrhosis, solid organ transplantation, active chemotherapy) were excluded. There were no significant differences in SPR based on age, sex, BMI, diabetes mellitus, chronic kidney disease, history of remote anti‐HBV surface or core antibody positivity, or prior HBV vaccination (Table 2). Lower current and nadir CD4+ counts were associated with progressively lower SPRs (P for trend < 0.0001 for both) (Figure 1). Conclusion: The SPR from HBV‐ISS in PWH appears comparable to the immunocompetent patients included in RCTs, especially when patients with significant non‐HIV immunosuppression are excluded. The SPR demonstrated in this single‐arm, retrospective study was higher than that of HBV‐Eng in immunocompetent patients, and consideration should be given to establishing HBV‐ISS as first‐line HBV vaccination in PWH. Finally, SPR is significantly reduced in those with lower current and nadir CD4+ counts. Further research on the effectiveness of a repeat vaccination series or higher dosing in these subgroups is needed.