Importance: Active immunization for hepatitis B virus (HBV) infection is recommended in patients living with HIV. Limited evidence is available about the most appropriate regimen of HBV vaccination among those who have not responded to an initial schedule.
Objective: To determine the efficacy of a high-dose schedule compared with a standard dose of HBV vaccination.
Design, setting, and participants: This double-masked, parallel-group, randomized controlled trial included patients living with HIV at a single outpatient HIV and hepatology clinic in Chile for whom previous HBV vaccination had failed. Patients with hepatitis B surface antibody (anti-HBs) titers less than 10 IU/L after an initial HBV vaccination regimen were included. Consecutive patients were recruited between December 2013 and March 2018. Data were analyzed in June 2018 using intention-to-treat analysis.
Intervention: The high-dose HBV vaccination group consisted of 3 doses of 40 μg recombinant hepatitis B vaccine at 0, 1, and 2 months. The standard-dose group received 3 doses 20 μg each at 0, 1, and 2 months.
Main outcomes and measures: Primary outcome was the serologic response to HBV vaccination (anti-HBs greater than 10 IU/L) 4 to 8 weeks after completion of the schedule. Secondary outcomes were anti-HBs greater than 100 IU/L and seroprotective anti-HBs at 1 year follow up.
Results: A total of 107 patients underwent randomization (55 to the standard-dose group, 52 to the high-dose group); 81 (75.7%) were men, and the mean (SD) patient age was 47.0 (13.3) years. Nearly all patients were receiving antiretroviral therapy (105 patients [98%]) and 92 patients (86%) had an undetectable HIV viral load. Mean (SD) CD4 count was 418 (205) cells/mm3. There were no differences in baseline characteristics between groups. Serological response in the high-dose group was found in 36 of 50 patients (72%; 95% CI, 56.9%-82.9%) compared with 28 of 55 patients in the standard-dose group (51%; 95% CI, 37.1%-64.6%) (odds ratio, 2.48; 95% CI, 1.02-6.10; P = .03). Mean (SD) anti-HB levels were 398.0 (433.4) IU/L in the high-dose group and 158.5 (301.4) IU/L in the standard-dose group (P < .001). Of patients with a serological response in the high-dose group, 29 of 36 (80.6%) had anti-HBs titers greater than 100 IU/L compared with 14 of 28 responders (50.0%) in the standard-dose group (P = .02). At 1-year follow-up, 20 of 25 patients (80.0%) with a serological response in the high-dose group had protective anti-HBs vs 9 of 23 patients (39.1%) in the standard-dose group (P = .01).
Conclusions and relevance: The results of this randomized clinical trial suggest that use of a high-dose regimen for HBV revaccination for patients with HIV achieves a higher and longer-lasting serological response as compared with a standard-dose regimen.
Trial registration: ClinicalTrials.gov Identifier: NCT02003703.