I've been on cosentyx for 3 years and have gotten flu vaccine, I haven't had any adverse reactions to it. I find it helps me not get as sick when I do catch the flu bug. Everyone is different in reactions to different meds, vaccines and preference to get one or not.

I guess you can, because when I was on it my doctor always asked if I wanted a flu shot. I, myself have always refused the shot regardless of what medications I was on. That’s just my personal preference