The anti-PreS1 and S antibody responses elicited by different regimens detected after first immunization (A–B) or second immunization(C–D).

<p>Each group received a different prime–boost vaccination, and antiserum was collected 2 weeks after the each immunization. Total HBV antigen-specific IgG titres were determined by ELISA. The symbols represent the titers of the sera from the individual mice. The horizontal lines represent the means (n = 6). The statistic significance of the results was analyzed and indicated as *<i>p</i><0.05.