Vaccines can have dire reactions. I'll never forget my first yellow fever one, many years ago. The night after I was given it, I woke up at about 2am on my back on the kitchen floor with five cats staring at me. Angels and weird creatures were flying overhead and I lay in a puddle of sweat. I think it may have been a 'mild' version of the disease itself. Luckily, the rules for yellow fever vaccination now say that one jab lasts for life (if it doesn't kill you first!).
I don't want Covid obviously, but I'm shielding anyway, and there aren't many cases in our area. Husband says he'll have the vaccine 'like a shot' (pun intended) because he works in a high school.