- 1University of São Paulo School of Medicine, São Paulo, Brazil.
- 2University of Southern California, Los Angeles, United States.
- 3University of California San Francisco, San Francisco, United States.
- 4University of São Paulo School of Medicine, São Paulo, Brazil. Electronic address: firstname.lastname@example.org.
Introduction and objectives: Some studies suggest chronic HCV infection diminishes responses to the anti-HBV vaccine. We evaluated the efficacy of double versus standard dose HBV vaccination among HCV patients without cirrhosis.
Patients and methods: 141 adults with untreated chronic HCV were randomized to HBV vaccination with double dose (40μg) or standard dose (20μg) at 0, 1 and 6 months; 70 healthy HCV-negative patients given standard dose served as controls. Vaccine response was defined by anti-HBs ≥10 mIU/mL.
Results: 128 patients (60 double, 68 standard doses) completed the study. Patients were of median age 52 years, 61% female, 60% fibrosis <2 of 4, and 76% genotype 1 with median 6-log 10 IU/mL HCV RNA. Overall seroprotection rate was 76.7% (95% CI: 65-87) in the 40μg versus 73.5% (95% CI: 63-84) in the 20μg dose HCV-positive groups (p =0.68) and 91.2% (95%CI:84-99) in HCV-negative controls (p =0.011 and 0.003, respectively). In multivariate logistic regression, vaccine dose (double vs. standard dose) was not associated with vaccine response (OR=0.63, p =0.33). Of 32 HCV-infected patients who were non-responders to 3- doses, 25 received the fourth dose of vaccine. The fourth dose seroconversion rate for the 40μg and 20μg groups were 45.5% and 21.4%, respectively.
Conclusions: In HCV-infected patients without cirrhosis, impaired responses to HBV vaccination cannot be overcome by the use of double dose HBV vaccination, but adding a fourth dose of vaccine for non-responders may be an effective strategy. Other adjuvant measures are needed to enhance seroconversion rates in these patients.
Trial register: U 1111-1264-2343 (www.ensaiosclinicos.gov.br).