Definitely get your flu shot!! A serious illness can result in a relapse.
Yes, I have had flu shots with no adverse effects.
I'll note, however, that some people say the nasal mist vaccine may not be the best choice. Get the actual shot.
Absolutely! I get mine every year! Make sure you get the injection, though, and not the "FluMist", which is a live attenuated vaccine. Since I'm on Tysabri, the pharmacist at the hospital told me not to get the flu shot until at least a week after my infusion. For those on CRABs (Copaxone.Rebif, Avonex, and Betaseron), or Gilenya, there are no time restrictions.
Be Well,
Lisa