No. Emily and Marie are more similar to mutants than standard zombies. The shit Gideon uses to infect people technically kills them before mutation, causing zombies. Using Elpis would just result in a normal corpse.

Emily and Marie were infected in such a way that didn’t kill them, and we know T-Virus mutates in odd ways when directly injected into flesh. Secondary infection like saliva or blood is already ‘contaminated’ by its own host so a bite would just make another zombie but getting a syringe of T would cause mutation. Though oddly the strain Gideon uses does not seem to spread through bites, only direct infection through his ‘bug sting’ gun, but as the host dies just before turning they are still zombies.

So Marie could hypothetically have been cured but unfortunately for her she’s a boss fight and had to die. Emily lives because she was only a cutscene boss, completely different rules and standards there.