[header] How to take legal action if an employer forces you to get a flu shot [title] Check if you belong to a union. [step] Your union contract may limit your employer's ability to force you to get a flu shot. This contract is called a " collective bargaining agreement. 
" you should check whether you are in a union and read any collective bargaining agreement. If your employer tries to force a flu shot requirement on you, you can bring a lawsuit in court.