Similar to immunity certificates, there are also the wider ethical implications of private businesses creating and enforcing vaccine mandates, according to Dr. Daniel Goldberg, an attorney and associate professor at the Center for Bioethics and Humanities at the University of Colorado Anschutz Medical Campus. “We are talking about differentiating groups of people, and permitting private actors to basically discriminate against them — to bar access on the basis of immunity status,”  he tells Rolling Stone. “That, in and of itself, is perilous.”