The invention relates to mecamylamine or a composition comprising mecamylamine, for use in the therapeutic treatment of an animal or a human patient presenting with a disorder of the central nervous system, said animal or patient being suspected of having an infection by a pathogen which triggers immune unresponsiveness, or for use to restore immune response in said animal or said human patient. In a particular embodiment, the invention is directed to mecamylamine or a composition comprising mecamylamine, for use to treat established rabies in a human patient or to treat a human patient presenting with clinical symptoms of rabies.