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

Our results showed that the Ad-UMAS vaccine could effectively improve the humoral response intramuscular pathway. Systemic humoral IgG antibody responses induced by the intraoral and intranasal vaccination pathway were comparable to those induced by the other pathway in the collected mouse sera. Interestingly, we found that IgG antibody in the intravenous vaccination group increased very sharply at first but slowly later on, even after the boost immunization. It should be considered that antigens that are transmitted to the bloodstream directly can induce strong immune responses in the early stage, but can also cause immune tolerance, explaining why antibody levels increase slowly in the following time [25] .