Vaccination with recombinant adenovirus expressing multi-stage antigens of Toxoplasma gondii by the mucosal route induces higher systemic cellular and local mucosal immune responses than with other vaccination routes

Wang, Ting; Yin, Huiquan; Li, Yan; Zhao, Lingxiao; Sun, Xiahui; Cong, Hua

To assess the systemic humoral immune responses obtained with the five immunization routes of Ad-UMAS, we collected sera at different times after the immunization, and anti-T. gondii IgG and IgG subtypes were detected by ELISA. As shown in Figure 2A , the levels of antibody titers all increased in the five Ad-UMAS immunization routes. Compared to the control, levels of T. gondii-specific IgG antibodies increased dramatically in the sera of all vaccination mice from day 14 to day 35 and achieved the highest on day 49 (p < 0.05). Among different immunization routes, the intramuscular group achieved the highest titer of IgG antibodies, then the subcutaneous, nasal, and oral groups, in decreasing order (Fig. 2B) . In the intravenous vaccination group, the titer of IgG increased rapidly at 2 weeks and gradually more slowly thereafter, making the final titer relatively low.