This area seems to be so gray.
My employer took this route:
1.set up 2 times for staff to get the shot - those not on duty were expected to do it on their own time.
2. those that had doubts or refused were ordered to go to their PCP for patient education (=get the shot) on their own time & pay the affiliated co-pays. A date & time were given in which staff had to notify the employer of when & with whom the appointment was made.
3. Those staff were further ordered to write a written report as to what was discussed, with whom, and outcome (shot received or not).
4. Those that had concerns on religious grounds were peppered with many emails about the Pope & others saying it was okay to get it for, 'the greater good.'

In my own case I did inform my supervisor of when my appt was before the set date/time. He sent it to the CEO via an email, which she never read. I then received a nasty email saying I would at a minimum not receive my annual raise and could be terminated for insubordination.
I never received an apology for HER fuckup and snotty email.