Originally posted by Nicholas D. Wolfwood
Zack did have a bit less of a reaction to the Jenova cells than cloud did, but that's because he's stronger, and his body was able to handle it. He still has them, and they still work. They just don't take him over and control him like they do to cloud.
Zack didn't have "a bit less of a reaction" than Cloud. According to Hojo's notes, he had no reaction at all.