The problem with the white blood count and Tecfidera is that the Lymphocytes, which are supposed to dip initially, do not come back to within normal levels. The Lymphocytes are the type of white blood cell which fight against viruses.
Once the Tecfidera is stopped, the Lymphocytes do recover. It can take several months but, once they have recovered you will be able to go on a different DMD.
It happened to me with Tecfidera, and unfortunately that was my fourth try of a DMD, so ultimately that was the end of the road for me and DMDs.
It’s not a major issue, I missed out on the flu virus that year, just in case, but didn’t get any more colds or other viruses than usual (probably just one cold through the winter).
So I wouldn’t necessarily see the risk of Lymphocytes depletion as a terrible side effect.
Equally, so long as you rotate your injection sites (and I think avoiding an automatic injector is also best because it is a bit more violent than just gently sliding the teeny little needle under the skin), Copaxone shouldn’t give any side effects. In fact, if the relapse reduction rate was a bit more equal between Copaxone and Tecfidera, I’d go for Copaxone every time.
Best of luck with your choice. Don’t forget, it’s not a diffficult thing to change drugs if one doesn’t suit you.