Used in the prevention and treatment of rabies by neutralizing the rabies virus before it can infect cells. It is administered as part of post-exposure prophylaxis, especially in individuals with severe exposure or compromised immune systems. Works by binding to the glycoprotein on the surface of the rabies virus, blocking viral entry into nerve cells. Often used in combination with rabies vaccine to provide immediate passive immunity while the vaccine stimulates active immunity. Critical in reducing mortality when given promptly after exposure. Additionally, it is used in research and development of new vaccines, as well as in laboratory diagnosis of rabies.