Inactivated West Nile Virus Lineage 2 (B-956 Uganda)

West Nile virus (WNV) is a single-stranded, positive-sense RNA virus belonging to the genus Flavivirus in the family Flaviviridae. The virus is enveloped, approximately 50 nanometers in diameter, and is characterized by an icosahedral capsid enclosing an approximately 11 kb genomic RNA. Its genome encodes three structural proteins—capsid c, precursor membrane (prM), and envelope (E)—as well as seven nonstructural proteins (NS1-NS5) that are essential for viral replication and immune evasion. The E protein mediates viral entry into host cells by binding to receptors such as DC-SIGN and integrins, followed by clathrin-mediated endocytosis.

WNV is primarily transmitted through the bite of infected Culex mosquitoes, with birds as its primary reservoir. Humans and horses are incidental dead-end hosts. The virus replicates in the salivary glands of mosquitoes and dendritic cells in the skin of vertebrates before disseminating to lymphoid tissues and blood. In humans, West Nile virus (WNV) crosses the blood-brain barrier and causes severe neuroinvasive disease, such as encephalitis or meningitis, in less than 1% of cases. Most infections (approximately 80%) are asymptomatic, while 20% present with West Nile fever (fever, headache, fatigue).