Board Thread:Manga/@comment-26495049-20180831081518/@comment-37493549-20181113022652

I think the point with Zeke is he injected his OWN spinal fluid into people, not his TITAN's spinal fluid. Human spinal fluid doesn't turn people into titans, or evaporate quickly or any of that. It just establishes a connection between them and Zeke so that he can transform them with his scream ability.

If he injected his titan's fluid into them they would have just transformed right away like how titans are normally created.