Hi Linda -- I also signed up to be in the new Stratify trial and get my blood tested every 3 months. I don't know how many vials they want because I'm JCV -

Congrats on 90-whatever! I realized that even though my infusion number is in the 40s, I will have been on Tysabri for 6 years come this July. It's hard to believe. If I had stuck to every 4 weeks I'd be at approximately #75! But the every 8 weeks seems to work great and keeps the UTIs at bay.