Yeah, supposedly, the flu shot is"dead" viruses used to teach the immune system. You get mild symptoms as your immune system reacts, but then is gone.
Some flu shot nasal sprays are active flu virus. Some people get actual flu from that.
But, hey, it's optional. Many reasons to get, many reasons not to get.
Besides the shot only helps if the strain selected is the one going around, and your immune system actually responded to the shot and got prepared.
I have skipped the shot some years, and got it some years. So for me is spotty.
I just remember one bad year.....when we couldn't afford health care...
Only once did I get the full blown flu, and I ran a fever of 103+ for 3 days, all my joints were swelled, and I was in extreme pain, couldn't hold food or water down. Had to use the restroom every 30 min. Coughed a lot and sweated like crazy. That happened when I was 13? Never been the same since. Now I have arthritis everywhere. Not sure if it is connected. I was out of commission for 2 weeks.
Ever since that I have tried to get the shots. Ever since that year I have not had that happen to me again.
My 2 cents.