Objective:A recombinant adenoviral vector vaccine based on non-replicating human adenovirus type 5 (Ad5), encoding the conserved domain of respiratory syncytial virus G protein (RSV-G) was constructed. The immunogenicity and protective efficacy of this vaccine were subsequently evaluated in mice.Methods:The recombinant Ad5 vector plasmid (Ad5-Gbcc-Gacc) was constructed by inserted conserved domains of RSV A and RSV B. The recombinant adenovirus Ad5-Gbcc-Gacc was rescued in HEK293A cells. The genome of virus Ad5-Gbcc-Gacc was identified by multi-enzyme digestion, and the expression of Ad5-Gbcc-Gacc was verified by Western blot. Recombinant adenovirus was used to immunize BALB/c mice via intramuscular injection with signal dose, and then challenged with RSV Long strain at week 6. The levels of G specific IgG and antibody subtypes in serum were detected by enzyme-linked immunosorbent assay, the level of neutralizing antibodies was determined by micro-neutralization assay. After challenge, the mice′s weight was recorded daily, the copies of RSV virus in the lung and nasal tissues were detected. Pathological changes in lung tissue were also examined.Results:Western blot and multi-enzyme digestion identification confirmed the successful rescue of the recombinant adenovirus. Ad5-Gbcc-Gacc elicit high titers of specific IgG, robust neutralizing antibodies, and a balanced Th1/Th2 immune response in mice. In comparison to unimmunized controls, mice immunized with Ad5-Gbcc-Gacc reduced the viral copies in both lung and nasal tissue, and exhibited only minimal pathological damage of lung tissue following RSV challenge. In conclusion, Ad5-Gbcc-Gacc induced robust immunogenicity and offers protective effects against RSV infection in murine models.Conclusions:Ad5-Gbcc-Gacc induce robust immunogenicity and can protect mice from RSV challenge, which lays a foundation for further development of RSV vaccine based on G protein.