In an act of bioterrorism, Jake's mercenary comrades were infected with the "C-Virus".
Mi opinion: La sangre de Wesker y de Alex es especial en el sentido que se puede adaptar al virus progenitor o sus variantes. Eso explica como lograron sobrevivir al virus experimental y tambien explica como logro sobrevivir Jake al virus C.It sounds like Jake's powers come from whatever was given to the anti-government troops (who consequently become disfigured). The Famitsu article states that Jake doesn't suffer from it, so he likely adapted to it.
Caray como kiero la traduccion de ese articulo de Famitsu.