Efficacy Evaluation of Virus Clearance of SYN023 in A Murine Rabies Model - China, 2025.

What is already known about this topic?: Rabies is a fatal, but preventable, viral disease. Post-exposure prophylaxis (PEP), which includes the administration of passive immune preparations, is critical after exposure to the rabies virus, particularly in high-risk cases. The delayed or missed application of passive immunizing agents may increase the risk of infection.

What is added by this report?: SYN023, a novel anti-rabies monoclonal antibody cocktail, can effectively reverse the course of rabies infection, even at a late stage of the disease. In a mouse model infected with the rabies virus strain SC16, multiple high-dose injections of SYN023 administered 5 days post-inoculation rescued 69% of the animals.

What are the implications for public health practice?: These findings suggest that SYN023 could serve as a promising therapeutic agent for rabies PEP, particularly in cases in which treatment initiation is delayed. This study provides a scientific basis for future clinical trials aimed at improving rabies treatment protocols.