I got my booster a week and a half ago.
I'm also on Cosentyx ( which I love).
The side effects were similar to what I had after the 2nd shot.
A bit of fever for a day and wiped out for a couple of days.
In my area we're having quite an outbreak and I'm seeing lots of vaccinated people getting sick. Mostly those who were vaccinated 5-6 months ago or more, so. .....
I'm glad I could get the booster.