Do I have the flu?

We received an email last week that it is mandatory for all employees to get a flu vaccine this year. I work for a hospital (NOTE: our office is NOT located in the hospital, nor do we have any direct contact with patients). I do not believe in them, as the shot does not protect against every strain of flu out there. I have never had a flut shot and never had the flu. Can they really force us to get this shot? I feel like this is an invasion of my personal, private, health.