Discretion, not discrimination

You can also be denied a transplant for bad hygiene, missing appointments, being too old, or any other reason that makes them think you wouldn't get the most out of the organ. Not following your doctor's instructions is definitely going to kill your chances - if you refuse to be vaccines, what happens if you decide maybe you don't need to take your immunosuppressants? Or you decide you could probably drink a bit just this once, no matter what your doctor said. You can destroy a transplanted organ with one bad decision

A new organ isn't a right or a privilege, it's triage. There aren't enough to go around, so medical ethics dictate you first save people who are dying, but are most likely to be savable - refusing a vaccine is a serious risk factor