Laura González-Hombrado

To evaluate the response to hepatitis B virus (HBV) vaccine in patients on biological therapy. Adults with autoimmune inflammatory diseases on biological therapy such as anti-TNFα, rituximab, tocilizumab, abatacept, or anakinra were included. Hepatitis B surface antibody (anti-HBs) was measured by ELISA before and after vaccination. Seroconversion was considered when an anti-HBs titer > 10 mIU/mL was achieved. The effect of treatment on the immunoprotective state was studied. The response was compared with that obtained in patients on synthetic disease modifying anti-rheumatic drugs (DMARDs) and healthy controls. A total of 187 patients on biologicals, 48 on synthetic DMARDs, and 49 on healthy controls were analyzed. More than 80% of patients on biologics responded to the vaccine but required more boosters and second vaccine series. Patients who achieved seroconversion were younger than those who did not (47.10 ± 12.99 vs. 53.18 ± 10.54 years, p = 0.012). Being on etanercept or golimumab was associated with seroconversion, while being on rituximab was not. Seroconversion was achieved in 93.75% of patients on synthetic DMARDs and 97.96% of healthy controls. The seroconversion rate in the biologics group was lower than in the synthetic DMARD group (p = 0.043) and tended to be lower than in the healthy group (p = 0.056). In patients on biological therapy, a high rate of HBV vaccine response can be achieved when a complete vaccination schedule is administered. Vaccination while not on biological agents reduces the requirement for boosters and revaccination. Key points: • Patients on biological therapy can achieve high rates of immune response to HBV vaccine when complete vaccination schedules are administered. • However, to achieve such a high seroconversion rate, more boosters and second vaccination series are required. • This supports the proposal already made to provide HBV vaccination to all patients with an autoimmune inflammatory disease after the diagnosis is made and not when the use of a biological treatment is under consideration.