Specific antibody response induced by DNA immunization with pTgDPA compared to pVAX I, PBS and blank controls using indirect ELISA. (A) Total IgG was evaluated in sera samples collected at 3 time points marked as week 0, week 2 and week 4 (n = 5). levels of: (B) IgG1(C) IgG2a, (D) IgA, (E) IgM and (F) IgE in sera samples collected at week 4 of the experiment (n = 5). (G) Comparison of the distribution levels of IgG1 and IgG2a subclasses in sera of pTgDPA vaccinated group after the booster dose. In all experiments, comparison results were expressed as means ± SD of OD450. The asterisk designates statistically significant differences (p < 0.05) between groups.