Real-World Effectiveness of Zamerovimab and Mazorelvimab and Vaccine for Rabies Grade III Exposure in Nanyang

Overview

The objective of this real-world, prospective observational study is to evaluate the clinical effectiveness of zamerovimab and mazorelvimab injection (a human rabies monoclonal antibody cocktail) administered in combination with a standard rabies vaccine for post-exposure prophylaxis (PEP) in individuals with WHO Grade III rabies exposure in Nanyang City, China. 1. The study primarily aims to assess: 2. The 3-month rabies-free survival rate following PEP initiation. 3. The 1-year long-term rabies-free survival rate. The rabies virus (RABV) carrying rate and genomic epidemiology among offending dogs involved in single-dog multiple-bite incidents. Eligible participants aged 18 years or older who have sustained a Grade III exposure from a tracked multi-person canine attack event, and have completed wound debridement and initial passive/active immunization within 24 hours prior to screening, will be followed for up to 1 year via telephone or clinic visits to monitor clinical survival.

This prospective, multicenter registry study evaluates the real-world deployment, clinical protection, and safety profile of zamerovimab and mazorelvimab injection (ZM cocktail)- containing two non-overlapping human monoclonal antibodies-in community emergency settings. Rabies presents a near 100% case-fatality rate upon symptom onset, making immediate and high-potency passive immunization essential during the active-vaccine immunity window (Days 0-7). Recent regional epidemic resurgences underscore the public health urgency of handling single-dog multiple-bite clusters, where furious rabid animals carry high viral loads and inflict multiple deep lesions.Approximately 80 patients receiving routine post-exposure care will be enrolled. Participants will receive standard-of-care wound debridement, anatomical infiltration of the ZM cocktail, and a full rabies vaccine regimen. Joining this registry involves no additional clinical interventions beyond standard medical care; investigators will actively maintain follow-up contacts at 3 months and 1 year to document survival outcomes. Concurrently, trapped offending dogs will undergo molecular verification via reverse transcription polymerase chain reaction (RT-PCR) and next-generation sequencing (NGS) to map localized viral ecology, providing crucial real-world data to optimize outbreak emergency response frameworks.