Apocalypse: Symbiote Genesis

It’s 150 years, give or take, since the Zombie Apocalypse. Your family has dedicated itself to understanding what makes zombies… um… zombies. There’s a symbiote/parasite that animates the zombies. Building on the research of your parents and your grandparents, you have isolated the parasite and can engineer strains to do almost anything: Super-strength and speed? Sure. Enlarged attributes and obedience? Yep. Powerful pheromones? Yep. Phenomenal regeneration? Sure! You wake up on a cold winter day in your bunker/lab to the buzzing of the “doorbell” of the outer airlock of your laboratory. What do you do?