A replication-deficient live vaccine candidate against the rabies virus infection in mice

Generating recombinant viruses lacking an essential gene for producing infective viral particles represents a promising approach to developing safer live viral vaccines. The envelope-spikes glycoprotein (G) of rabies virus (RABV) plays a critical role in mediating viral adsorption and entry into host cells, making it a key factor influencing its pathogenicity. Herein, we focused on constructing a replication-deficient rabies virus (RABV) with a specific G gene deletion (rSRV9-△G-eGFP). This engineered virus is incapable of forming plaques in cells unless supplemented externally with the G protein, confirming its status as a single-cycle virus producing non-infectious progeny. Despite this restriction, rSRV9-ΔG-eGFP efficiently initiated host immune activation following immunization. Notably, vaccination induced pronounced recruitment and activation of antigen-presenting cells, as well as enhanced T and B lymphocyte responses, highlighting a strong cellular immune component that distinguishes this platform from traditional inactivated rabies vaccines. Consistent with protective immunity, rSRV9-ΔG-eGFP elicited virus-neutralizing antibody titers exceeding the accepted protective threshold of 0.5 IU/mL and conferred protection against lethal RABV challenge. Together, these findings support rSRV9-ΔG-eGFP as a promising replication-deficient rabies vaccine candidate and suggest its potential utility as a viral vector platform for future vaccine development. • A replication-deficient rabies virus (rSRV9-△G-eGFP) was engineered by deleting the G gene, rendering the virus incapable of producing infectious viral particles while still being able to replicate and elicit immune responses. • Immunization with rSRV9-△G-eGFP elicited neutralizing antibodies exceeding 0.5 IU/mL and protected mice from rabies virus challenge. • The recombinant virus platform exhibits good safety.