The progenitor virus had a very short lifespan in the air.
Its spread quickly halted, and the virus naturally died out.
The Bald Eagle agent was also not a chosen target of the progenitor virus; he merely served as a temporary carrier.
Ultimately, only Lulu and Allen were infected.
"The effects of the progenitor virus are probably known only by the people of the country where it first infected, and unknown to others," said Professor Piers.
"That country is quite undeveloped, with only a few towns and mostly tribal villages."
"By now, that country has been overtaken by zombies, likely not a single living person remains unless someone goes there to see for themselves, no one knows what might ultimately happen."
"The reason I entrusted Lulu to you is partly because I sensed something in you that resonates with the progenitor virus."
"Additionally, having such critical research subjects like Allen and Lulu in the same team is risky."