Really, calling whatever drug therapy they're trying to develop a "vaccine" is a misnomer. If I'm not mistaken, a vaccine protects you from contracting a disease in the first place, usually a contagious one (flu, measels, malaria, etc etc). In order to prevent someone from getting Celiac disease, you'd have to change their genetics!!
Just a point.
And yeah, wherever this "90%" business is coming from, I'd like to know. Eating entirely gluten free is NOT impossible. A lot of work, but we do it.