Sabriel's zombies range from possessed corpses that are indistinguishable from normal zombies to things with human/near human intelligence to undead flocks of crows, possessed fiery golems, and almost-invincible undead sorcerers. And rather than a virus, it's all magic. (I don't think Sabriel even knows what a virus is.)

Also, she's due to run into zombie-Clem during a Hellrena, so Wesker could also interrogate her about her ability to control the undead using music/sound?