Where I work, the flu shot is mandatory.
It doesn't mean we get fired if we don't get it or that they hold us down while jabbing at our left arm like my dad did to me when I was 16 and didn't want a flu shot. What it does mean is that if you don't get a flu shot, then during the entire flu season, you are required to wear a mask in patient care areas.
In addition to the mask, you also have to wear a badge that explains why you aren't wearing the mask. The badge says "I'm wearing a mask because I care about your health." That doesn't sound so bad, except underneath that statement is a picture of the cartoon pig wearing a mask.
Personally, I am in favor of mandatory flu shots for everybody who is capable of getting it. I have heard a lot of the reasons people don't get flu shots and I think most of those reasons are dumb, in all honesty. Most of the reasons are something along the lines of, "I never got a flu shot and I have never gotten the flu before so why should I get a flu shot?" Or, "I got the flu shot once and got sick right after, so I will never get a flu shot again."
That said, if someone has a really good reason for not getting a flu shot, like a history of Guillain-Barre, then I'm not sure it's fair to restrict them like that. I mean, wearing a mask for four months straight really sucks.