This study will test an experimental drug called MGAWN1 for the treatment of West Nile infections.

The objective of this study is to provide expanded access to MGAWN1; the study is not intended for subjects who are eligible for and have access to non-expanded access protocols.

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