Immunogenicity of the hepatitis B vaccine adjuvanted with AS04C in patients with biological therapies

Background: Hepatitis B vaccination is necessary for patients with biologic therapies because of the immunomodulatory effect of these drugs. Due to the elevated use of these therapies in the latest years, the research for new vaccination regimens and the improvement of the current ones is essential. New adjuvants like AS04C might be a potential strategy to improve immune response. Hepatitis B vaccine adjuvanted with AS04C has not been studied in this population before. We analyzed the immunogenicity of an adjuvanted hepatitis B vaccine in patients with biologic therapies. Variables that might affect vaccine response were also evaluated.
Methods: Analytic observational retrospective cohort study performed between January 2016 and September 2018. 301 patients under biological treatment aged from 18 years were included. Patients received 4 doses of hepatitis B adjuvanted vaccine (Fendrix®) in a 0-1-2-6 month immunization schedule. Several sociodemographic, clinical and pharmacological variables were evaluated. The outcome variable was measured as the antibody titers (anti-HBs). The geometric mean of titers (GMT) as a measure for the central tendency was calculated from these values.
Results: The immunization schedule of the hepatitis B vaccine adjuvanted with AS04C demonstrated high levels of seroconversion with 82.1 % (95 % CI, 77.6-86.6) of vaccinated patients seroconverting after primary vaccination and achieving 89.0 % (95 % IC, 85.3-92.7) after the booster doses for non-responders. The use of corticosteroid therapy and high doses of them, age over 60 years and the main diagnosis were associated with lower seroconversion rates and lower anti-HBs titers.
Conclusions: The hepatitis B vaccine adjuvanted with AS04C (Fendrix®) produces an adequate immune response in patients with autoimmune diseases and immunosuppressive and/or immunomodulating therapies. This immunization schedule is proposed as a very suitable and adapted option for the protection of patients with autoimmune diseases under active biological therapies.