ABSTRACT
Objective To investigate the genetic stability, immunogenicity and protective efficacy of AdC68-rab. gp, a novel rabies vaccine based on the replication-defective chimpanzee adenoviral vector AdC68-ept. Methods The recombinant adenovirus AdC68-rab. gp expressing the glycoprotein of rabies vi-rus ERA strain was constructed. Genomes of the AdC68-rab. gp of different generations were extracted and analyzed. HEK293 and Huh7 cells were infected with the AdC68-rab. gp of different generations. ICR mice were immunized with the AdC68-rab. gp and blood samples were collected 4 weeks or 6 months after immuni-zation. Rapid fluorescent focus inhibition test ( RFFIT) was performed to detect the neutralizing antibody against rabies virus in mice serum samples. ICR mice were challenged with lethal dose of rabies virus 4 weeks after the immunization with AdC68-rab. gp to evaluate the protective efficacy of AdC68-rab. gp. Re-sults The genome of AdC68-rab. gp was stable after 15 passages, which was identical to that of the 5th and 1st generations. High levels of neutralizing antibody against rabies virus in serum samples were detected in mice immunized with AdC68-rab. gp and maintained for a long period of time. Immunization mice with one dose of AdC68-rab. gp could protect all mice from the lethal dose challenge of rabies virus. Conclusion The novel AdC68-rab. gp was characterized by good genetic stability and ideal protective effi-cacy. The adenoviral vector based vaccine could be further developed as a potential candidate for the substi-tute of current rabies vaccine.