Hi Overcomer, I was on Tysabri for about 9 months and it was great in the beginning! I wasn't having any flare-ups, no side effects, and I was able to finally live my life much more than I was able to on some of the other medications. However, I am 18 years old and the medicine may have been a little too strong for me because I started having some bad reactions to it about 3 months ago. My JCV was negative, which is very important for your doctor to test as you probably know.
I had my infusion of Tysabri last Thursday and had a really bad allergic reaction to it, so I have to stop receiving it and am taking benadryl and gabapentin for any other allergic reactions that may occur while the medicine courses through my body. If Tysabri is working for you, I say continue with it! It was working so well for me in the beginning and I had felt the best I have ever had in a very long time. The infusions can be exhausting and annoying, but if the medicine is working for you, you should really stick with it! Many times in the infusion room, I would meet people who had been on Tysabri for years with no problems and they have achieved so much and are living life relapse free!
I hope my story helped you out in some way! Good luck with your decision!!