I been on the planet long enough and never gotten a flu shot and rarely get sick! People who seem to get the shot get sick just as much as ones that don't if not more! More or less IMO shot gives you better chance of getting a slight case of the flu but nothing life threatening .......... meaning getting a shot prevents you from dying from the flu! The ones most suspect to die are the very young and very old!
Saulty's probably right with warm weather residents getting the flu a lot less than people residing in climate changing 4 season areas! Ask yourself, why does the flu shot come out now and not in say April or May? Like I said been around long enough and from my observation in NJ nobody is sick from early June to late September but all the flu cases arise from Nov to Feb/March!
During the summer only one time got the fever/flu many years ago and felt like I was going to die, worst sickness ever! Only reasoning was summer isn't the time to get sick so this must have been one doozy of a illness that nothing was going to prevent it! Maybe if I got it in the winter without a shot would have been lights out for me? Who knows, I'm not a doctor and some doctors I think don't know either!
With all that being said, depending how long I get up in years, might start thinking of getting a shot just not to die from the flu! That's what I believe from what I have heard and seen throughout the years!