Not judging you guys or anyone who gets shots
I think most people do and I know my parents get them
But I don't get sick often...maybe once every 3-4 years
Did get sick one time(appendix burst)...but I don't think it was a flu thing...I think it just wore out or something...probably got some food stuck in there LOL
If you get them one year are you supposed to keep getting them regularly?
To answer the last part...
Every year the flu mutates and so the scientists are basically making the vaccine for what they expect to encounter during that season. So they're playing the odds and hoping they're right.
So a vaccine from one year may not do a damn thing for the next bug that rolls through.
If you want to safeguard yourself against it to reduce it's effects or avoid it then you should get the new one every year.
But if you're hearing that the flu is especially nasty one year and want to get it but the next year you don't then that's just fine.
As I said before, I am required by hospitals to have it done or I can't do business there. I never got them before and probably wouldn't if it wasn't a necessity. But if my immune system was weak or I was old I would get it in a heartbeat.