 This study aimed to evaluate the anti-HBS persistence and immune memory 18-19 why after vaccination against hepatitis B in healthy individuals primed as infants or adolescents. The results showed that 67.9% of individuals had anti-HBS concentrations greater than or equal to 10 MIU ML with a higher antibody geometric mean concentration GMC in group B than in group A booster doses were effective in inducing an amnestic response in vaccines with anti-HBS less than 10 MIU ML, but further follow-up is required to assess the long-term protection. This article was offered by Luisa Romano, Christina Golly, Keisha Tagliacan and others.