Hepatitis B vaccine responders show higher frequencies of CD8+ effector memory and central memory T cells compared to non-responders.

Hepatitis B (HB) infection is a major global health problem. There is limited knowledge about HB vaccination-induced immune memory responses. We compared the frequency of CD8⁺ memory T cell subsets between responders (RSs) and non-responders (NRs) to HB vaccination. Blood samples were collected from RSs and NRs. PBMCs were cultured in the presence of Hepatitis B surface antigens (HBsAg) and PHA for 48 h to restimulate CD8⁺ memory T cells and T cell memory subsets were detected by flow cytometry using memory cell markers. The frequency of T_EM, T_CM, and T_CM ^hi was significantly higher in responders compared to non-responders (p = 0.024, 0.022, and 0.047, respectively). Additionally, we report a positive correlation between the frequency of T_EM cells in RSs with age and anti-HBsAb level (p = 0.03 and r_s = 0.5; p = 0.01 and r_s = 0.06). Responders display a higher level of CD8⁺ T cell-mediated immunity. Therefore, we suggest a possible defect in the formation of immunological CD8⁺ memory T cells in NRs and it may reduce antibody production compared to the RSs, although more experiments are needed.