1. Be aware what your state law says. In Texas, healthcare facilities can require Covid-19 vaccination, OR use of medical protective equipment (i.e. masks....) to prevent risk to patients, and even then only based on the staff member's routine and direct exposure to them. This must be defined on an individual basis. There are penalties for employers who do not adhere to the law.
2. For me, as the practice physician, I have chosen to be up to date on Covid (and flu) vaccination, as my education and information available to me was sufficient for that decision. Not everyone has a medical degree or can understand research data, and even those who do don't always agree. However, I bet most persons declining vaccination, who medically could be, would be vaccinated if you paid them a million dollars. So, if you are familiar with a certain Winston Churchill anecdote, can you follow that logic and consider offering a small bonus (financial or otherwise) for employees to get vaccinated?.
3. Your staff might be interested in Covid antibody testing, since some of them may have been inoculated via fomites etc. and have knowingly or unknowingly been infected already with the more recent strains. For these staff with demonstrable up to date anti-Covid antibodies I would consider them vaccinated until new strains with related vaccines are available. For other nonvaccinated staff I would just be extra careful (use PPE for direct patient care, avoid direct patient care for up to a week after any known positive contact, and consider limited patient care after extended public travel or crowd exposure (indoor concert and sports venues).
4. I suggest that you at least document that you asked your staff about getting vaccinated and you explained the pros (and discussed cons) with them and your policy for nonvaccinated employees. Remember, these vaccines are not 100% effective, and you cannot guarantee that other patients or visitors will not carry risk of infection into your office. However, making an effort to minimize risk, and documenting it is reasonable. So, having been reasonable, you can move forward and focus on patient care and the few other challenges that may arise from that... Good Luck!