Immune response to different types of hepatitis B vaccine booster doses 2 to 32 years after the primary immunization schedule and its influencing factors

Abstract Objective To assess the immune effect of different types of hepatitis B vaccine (HepB) booster doses 2 to 32 years after primary immunization, explore the influencing factors, and offer guidance regarding the necessity and timing of boosters. Methods In total, 1163 participants who were born from 1986 to 2015, received the HepB full-course primary vaccination, were hepatitis B surface antigen (HBsAg) and hepatitis B core antibody (anti-HBc) negative, and had hepatitis B surface antibody (anti-HBs) Results In total, 595 and 568 individuals received a single dose of HepB (CHO) and HepB (SC), respectively. Venous blood samples were obtained from 1079 vaccinees (CHO: 554, SC: 525). The seroconversion rates were 93.68% (519/554) and 86.67% (455/525) (p  Conclusions Participants boostered with HepB (CHO) had a relatively higher seroconversion rate than those boostered with HepB (SC). The high seroconversion rates in the two groups suggested that the subjects remained protected despite low circulating antibodies, so there is currently no urgent need for booster immunization. Factors including BMI ≥ 25 and prebooster anti-HBs concentration