Abstract
About 10% adult failed to develop antibody response after primary hepatitis B vaccination, and revaccination may be an option to improve immune response, but the antibody responses to revaccination in adult non-responders have not been fully examined. Adult non-responders to primary 3-dose hepatitis B vaccination were randomly divided into 2 groups and revaccinated with 20 μg hepatitis B vaccine (HepB) derived from Saccharomyces Cerevisiae (HepB-SC) or 20 μg HepB derived from Chinese hamster ovary cells (HepB-CHO), respectively, at 0-, 1-, 6- month. Seroconversion rate and titer of antibody against hepatitis B surface antigen (anti-HBs) was measured one month after the 1st and 3rd revaccination dose. Anti-HBs seroconversion rates significantly increased from 54.98% [95% confidence interval (CI) 48.60%-61.24%] after the 1st revaccination dose to 89.24% (95% CI: 84.74%-92.79%) after the 3rd revaccination dose (P < 0.001), and the geometric mean titer (GMT) of anti-HBs increased from 12.18 mIU/ml (95%CI: 7.81-18.98 mIU/ml) to 208.31 mIU/ml (95% CI: 148.87-291.47 mIU/ml) (P = 0.008).Compared with those with anti-HBs titer <2 mIU/ml after primary vaccination, those with antibody titer ≥ 2 mIU/ml after primary vaccination had higher seroconversion rate after the 1st dose revaccination (38.36% vs. 78.10%, P < 0.001) and after the 3rd dose of revaccination (84.25% vs. 96.19%, P = 0.003), and had higher antibody titer after the 1st dose of revaccination (3.32 mIU/ml vs. 74.21 mIU/ml, P < 0.0001) and after the 3rd dose of revaccination (145.73 mIU/ml vs. 342.34 mIU/ml, P = 0.01). Anti-HBs titer was significantly higher in those revaccinated with HepB-CHO than those revaccinated with HepB-SC after the 3rd dose (131.46 mIU/ml vs. 313.38 mIU/ml, P = 0.01). Revaccination on adult HepB non-responders increased the immune response to HepB and may confer further protection against hepatitis B virus infection. If possible, revaccination might be an option to HepB non-responders to secure more protection.