It is, of course, very much the employer's business - employers have the right to provide a safe workplace.
Respectfully, employees have the right to refuse to put anything they suspect will be bad for them into their own bodies,
without the threat of having their livelihoods taken away from them.
These new vaccines are not without sometimes serious risks, and they are proving to be quite unpredictable is some cases.
For example, in my own department I personally know of a man who has been in and out of recuperation since this past spring after voluntarily taking the Johnson and Johnson one...
He's never tested positive for CoVID-19, and he told me that if he had to do it all over again, he would not have taken the shot.
In addition, in the United States of America there is this thing called a "Constitution",
and it provides a Bill of Rights that protects individuals from government over-reach into people's personal lives, and it also allows for re-dress if something that governments, companies or even individuals do, leads to the injury or death of other people.
Thus far, my own opinion is that that document has been very much-ignored during this current trying time, by certain entities that seek to control something that is proving to be very nearly uncontrollable.
That said,
I will limit my replies to this subject from here on out, having made my opinions known.
As a United States Navy veteran with over 10 years of service ( both Active and Reserves ) and that has had his share of vaccines,
My own view is that I will not support vaccine mandates of
any kind, and I fully believe that such things should be left up to
individuals ( and parents in the case of children ) to decide...for better or for worse.
May God bless you sir.