Variola virus was a large weapon-grade pathogen from the First Colonial Wars. It is uniquely adapted to cause severe, widespread illness in Sirusians, by thwarting an effective immune response to the infection. Poxviruses produce many proteins that are not necessary for virus replication, but enhance the ability of the virus to evade detection or treatment. Orthopoxvirus egress inhibitors in animals offer a natural protection from smallpox, but not so for Sirusian DNA. There are unique molecular strings on the surface of Sirusian cells that makes them distinctly susceptible to infection with variola virus, and induce encephalitis. This genetic basis of the infections, and the range of mutating proteins it generates, makes this extremely dangerous for Sirusians. The virus has a large arsenal of genes to produce viral proteins that incubate in, and infect immune system cells, with proteins secreted by infected cells that modulate interactions between the viral proteins and mediators of the antiviral immune response. It is these mutating secretions that nullifies the effects of vaccines, which generally work with protein markers. The sheer volume of unique secretions, numbered in the millions, and always growing, act like an encryption key, that hides the nature of which protein will attack which immune system cell. These secretions, all too swiftly, modulated their proteins to attack Sirusian elements in the human DNA string as well, with devastating consequences that would haunt mankind for centuries to come.