I believe it has been shown that fully vaccinated people getting asymptomatic infections is rare.The big thing is that, once vaccinated, one may still become infected (typically with at worst, mild symptoms), and be a carrier host that passes it on to others. A disease vector. You know, like a deer tick passing on lyme disease. I haven't seen any convincing information that vaccinated persons are not potential carriers/transmitters.
At some point, once everyone has had a chance to be vaccinated, those who refuse are just going to have to live with being exposed and getting it. We can't go around protecting them from themselves forever.