ABSTRACT FINAL ID: 1812
TITLE: Impaired Anti-HBV Vaccine Response In Non-Cirrhotic Chronic HCV Patients Is Not Overcome By Double Or Additional (4th) Dosing
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This study was not sponsored
Background/Aims: Studies of HBV vaccination in patients with chronic HCV infection have demonstrated diminished anti-HBs responses ranging from 63.6% to 72.9% compared to 90.9% to 93.9% in healthy controls, suggesting HCV per se reduces vaccine responsiveness.
Aims: To determine whether double dose (versus standard) HBV vaccine(Butang®; Butantã Institute, São Paulo) and, in non responders, whether administration a fourth dose of vaccine improved anti-HBs responses in treatment naive chronic HCV patients without cirrhosis.
Methods: 140 adults with chronic HCV without cirrhosis were randomized to receive HBV vaccination at double dose (40ug at 0, 1 and 6 months) or standard dose (20ug at 0, 1 and 6 months). Response to vaccination was measured by titers of anti-HBs at 1 month after the last dose of HBV vaccine and response (seroconversion) defined by anti-HBs ≥10 U/L.HCV chronic patients who did not respond to primary anti-HBV immunization received a fourth single or double dose of vaccine based on original group randomized.
Results: 129 patients (61 standard dose; 68 double dose) completed the study, with no dropouts due to adverse events. Completed patients were of median age 51 yrs, 61% female, 52% White, 40% MetavirF2-3, and 75% genotype 1 with median 6log10 HCV RNA. The overall seroconversion rate was 76.3% (95% CI 65-87%) in standard dose and 73.1% (63-84%) in double dose groups compared to 91.5% (84-99%) in non-HCV controls (p=0.02 and 0.008, respectively). Among HCV patients, seroconversionwas not significantly different in the double vs. standard dose vaccination groups (p=0.69). Among responders, median anti-HBs titers in the double dose and standard dose vaccine groups were not significantly different from controls (205 vs 432 UI/L, p=0.66) and vaccine group (standard versus double dose) was not an independent predictor of vaccine response in regression modeling (OR=0.85, p=0.69). Among 23 HCV non-responders given a fourth dose of HBV vaccine, 7 seroconverted (30.4% CI 13.2-52.9) and seroconversion rate for the single anddouble dosegroups were 11.1% (n=1, 95% CI 0-48.2) and42.9% (n=6, 95% CI 17.7- 71.1) respectively (p=0.18) and median anti-HBs 30 days post-vaccine was higher in patients seroconverting with 4thdose (10 [IQR 7-11] compared to those seroconverting after 3 doses [IQR 2-2], p=0.001).
Conclusions: In HCV-infected patients without cirrhosis, responses to HBV vaccination are significantly impaired and this reduced response cannot be overcome by the use of double dose HBV or an additional four dose of vaccine.