Efficacy and Safety of Rabies Monoclonal Antibodies Compared with Rabies Immunoglobulin in Post-Exposure Prophylaxis: A Meta-analysis of Randomized Controlled Trials

Abstract

Introduction: Rabies is one of the deadliest infectious diseases, with a case fatality rate approaching 100% once clinical symptoms appear1. Presently, the WHO recommends vaccination for category II and III exposure as post-exposure prophylaxis (PEP) and the co-administration of rabies immunoglobulin (RIG) for category III1,2. However, frequent shortage and high price of RIG3,13 as well as safety concerns2 urgently call for more feasible alternatives. With the advent of a handful of studies evaluating the efficacy and safety of RmAb compared to RIG4-9, this review aims to compare the efficacy and safety of RmAb-based PEP versus RIG-based PEP by evaluating neutralizing antibody response.

Methods: Aligning with the PRISMA guideline, eligible studies were systematically searched through PubMed, Scopus, Cochrane, Epistemonikos, and Proquest from inception up to March 2026. This study is prior registered in PROSPERO (CRD420261346500). Risk of Bias was assessed using Cochrane's Risk of Bias (RoB) 2 tool. Meta-analysis was performed with a random-effect model with a 95% Confidence Interval (95% CI).

Results: Five randomized controlled trials were included in the analysis. The results show a significant difference in mean geometric concentration (GMC) of rabies virus neutralizing antibodies (RVNA) on day 14 after administration (MD: 10.20, 95% CI [2.62, 17.79], p = 0.008). However, no significant result was found on day 7, with a pooled MD of 2.05, 95% CI [-0.59, 4.68], and a p-value of 0.13. The adverse events outcome reveals no statistically significant difference between arms (MD: 0.91, 95% CI [0.75, 1.11], p = 0.37).

Conclusion: RmAb may prove to be more effective as a PEP compared to RIG. However, a conclusive safety outcome between arms remains to be assessed by future studies.