Respiratory syncytial virus (RSV) is a serious human respiratory pathogen that commonly affects children, older adults, and immunocompromised individuals. At present, the design of licensed vaccines focuses on the incorporation of the pre-fusion protein (PreF protein) of RSV, as this protein has the ability to induce antibodies that offer a high level of protection. Moreover, the G protein contains the CX3C motif that binds the chemokine receptor CX3CR1 in respiratory epithelial cells, which plays an essential role in viral infection. Therefore, incorporating the G antigen into vaccine design may prove more advantageous for RSV prevention. In this study, we developed a human adenoviral vector-based RSV vaccine containing highly neutralizing immunogens, a modified full-length PreF protein fused with the central conserved peptides of the G protein (Gcc) from both RSV subgroups trimerized via a C-terminal foldon, and evaluated its immune response in mice through intranasal (i.n.) immunization. Our results showed that immunization with Ad5-PreF-Qa-Gcc elicited a balanced Th1/Th2 immune response and robust mucosal immunity with higher neutralizing antibody titers against RSV Long and RSV B1. Importantly, immunization with Ad5-PreF-Qa-Gcc enhanced CD4⁺ CD25⁺ FoxP3⁺ Treg cell response and protected the mice against RSV infection. Our data demonstrate that the combination of Gcc and the PreF antigen is a viable strategy for developing effective RSV vaccines.

Rotaviruses remain the leading cause of severe dehydrating diarrhea and associated mortality in children under five years of age worldwide. The successful global rollout of live-attenuated oral rotavirus vaccines has dramatically reduced rotavirus gastroenteritis morbidity and mortality, unequivocally demonstrating their excellent safety profile and potent induction of mucosal immunity. These attributes highlight the substantial potential of rotaviruses as novel oral mucosal vaccine vectors. Recent breakthroughs in reverse genetics, particularly the establishment of a fully plasmid-based system in 2017, have enabled precise insertion and stable expression of foreign antigens at targeted genomic loci. This advance has opened a viable pathway for developing multivalent oral mucosal vaccines. This review traces the historical development of rotavirus reverse genetics and summarizes the latest progress in its application as a vaccine vector platform. We focus on key strategies for foreign gene insertion and immunological outcomes in animal models, while critically evaluating persistent challenges—virus rescue efficiency, genetic stability of inserts, and limitations of current animal models—and outlining the rational design framework for RV-based vectors with improved stability, expression efficiency, and immunogenicity.