Cindy, I first started with Copaxone in 1999, not big deal, no side effects, most of my ms is in disability in left leg Have had no ms flare-ups since optic neurotis in 1996, basically drop foot.2002 started both Copaxone & Avonex at the same time, since my ins at the time covered both my neur. wanted to test try both, after 1 yr of feeling like a pin cushion I said one or the other, I choose Avonex because it was 1 a week. The only side effect until this rebif fiasco was an occaional head ache. I have noticed when I'd miss a week of avonex my right leg gets numb. So as far as ms I can't complain until now. Rebif , Drs. should have a better understanding of the drug before they prescribe it, I got more info from the drug company after I had probelms than my current neuro. Rebif has 2 stregnths, one is the 44 the other is the 22 there is a choice , not just putiing you from 8 to 22 to 44. there also is 4,8 & 22. The rebif company recomends the 22 for people like me with mild systoms, I wish I had known that before my Dr automatically did the 8,22 & 44. Before Rebif Avonex was easy with an occasional headache, now I have had chills for 2 days & I'm still vibrating, like I said the vibrating isn't as bad but it is driving me crazy. I'm not drug sensitive but I'm also not use to have any kinds of issues with ms. The only good thing is, the side effects are drug related, not ms, but if I have to get off Avonex for any length of time to stop this vibrating, I'm not sure what that will do I hate insurance companies!!