I guess you could always take the prescription and just simply not fill it.
I'm not sure if your laws are similar to ours here, but no employer can force you to be vaccinated here, they can make it difficult though. When they tried this BS with me, difficult met more difficult, and they backed down. It amazes me how many so called 'mandatory' practices, turn out not to be mandatory at all, just preferred. We are told they are mandatory to make us comply.