I had my 1st dose of Covid between my 1st & 2nd initial vax’s (no side effects except a sore arm at site & with the 1st, a headache for 12 hrs) which was a mild flu type illness for 24-48 hrs.
I had my 1st Booster & 2nd Booster with no I’ll effects & then just before my 3rd Booster before last...