Well if Code Veronica was any indication, the founding fathers of Umbrella were all of English royalty and decendency. My "plan" was to create a believable use for the viruses that these guys created. It all had to start somewhere so I was thinking maybe some German general wanted to create sometime that would keep his men alive in the harshness of the trench so he heads to Romania with a Bacteriologist named Dr.Brand to some village where the people don't seem to get sick at don't age as much as normal people do.
You know, the road to Hell is paved with good intentions and all that so something goes horribly wrong (as usual) and now Klaus has to fight his way out of the village which is infected with this "proto-virus" while Von Kleist, now mad with the infection is planning on spreading the stuff throughout the Eastern Front under the guise of "small pox" vaccine. You can say this is where Ozwell and the other Umbrella guys get their idea for the virus.