Finally, any certificate that affords special status, like the ability to work while others are quarantined, will create incentives for people to deliberately infect themselves or game the system with counterfeits. Immunity passports would unfairly “favor individuals who didn’t comply with social distancing and got sick early on,” said Alexandra Phelan of Georgetown University, who works on legal and policy issues related to infectious diseases. And “the idea that there would be a midpoint where some people could resume the right to be citizens and others could not is effectively an apartheid system,” said Sharon Abramowitz, a consultant at UNICEF who studies community responses to pandemics. “It might serve specific public-health ends, but in this society would be very problematic.” History affirms that concern: When yellow fever hit the American South in the 19th century, “immunoprivilege” worsened existing forms of discrimination while creating new ones.