Expanded Access to MGAWN1 in Subjects With Suspected West Nile Neuroinvasive Disease; Suspected West Nile Virus Infection; or Substantial Accidental Exposure

Inclusion Criteria: 1. For West Nile Neuroinvasive Disease subjects: Have neurological signs and/or symptoms of West Nile meningitis, encephalitis, and/or acute flaccid paralysis 2. For immunocompromised subjects with suspected West Nile virus infection: * Receiving immunosuppressive treatment for any disease, such as autoimmune diseases, or transplant recipients; or * Have received organs or tissues or cells from donors likely infected with West Nile virus (as shown by serology or PCR/NAT from the donor, organs, or tissues) or * Have acquired immunodeficiency (other than from immunosuppressive treatment or from receiving infected transplants) or congenital immunodeficiency 3. For subjects with substantial exposure to West Nile virus: Exposure by any route, including percutaneous, inhalation, or mucosal exposure (such as might occur in a laboratory accident) 4. Develop signs and/or symptoms within 14 days before study enrollment