Objective:This study aimed to evaluate the immunoprotective effect of anti-rabies virus cocktail monoclonal antibody Zamerovimab/Mazorelvimab after rabies exposure.Methods:The dynamic data of rabies virus neutralizing antibody (RVNA) were analyzed in the Zamerovimab/Mazorelvimab Chinese phase Ⅲ study (clinical trial registration number: CTR20201819).Results:The full analysis set showed that RVNA geometric mean titers (GMT) on the 4 th, 8 th, 15 th, 43 rd, and 99 th day in the Zamerovimab/Mazorelvimab group were 4.413 IU/ml, 5.178 IU/ml, 17.062 IU/ml, 14.672 IU/ml, and 2.836 IU/ml, respectively, while those in the human rabies immunoglobulin (HRIG) group were 0.299 IU/ml, 0.451 IU/ml, 11.374 IU/ml, 18.063 IU/ml, and 6.769 IU/ml, respectively. The positive rates of RVNA on the 4 th, 8 th, 15 th, 43 rd, and 99 th day in the Zamerovimab/Mazorelvimab group were 99.9%, 99.6%, 100%, 100%, and 97.4%, respectively, while those in the HRIG group were 23.3%, 34.1%, 97.6%, 99.6%, and 98.4%, respectively. Conclusions:Compared with HRIG, Zamerovimab/Mazorelvimab cocktail monoclonal antibody reached the required protection level of RVNA very soon, thus effectively provided an immediate neutralizing effect of passive immunization therapies against rabies virus.