The debate over vaccine passports is often based on emotion rather than fact. But they are nothing new. Proof of vaccination is needed for overseas travel, certain health care jobs, as well as entry into schools and daycares. The yellow card was introduced in 1959. Travelers needed them to visit countries where they could be exposed to yellow fever, cholera or rubella. When the smallpox epidemic hit the U.S. in 1899, the hardest hit states put vaccine mandates in place. Dr. Peter Chin-Hong is an infectious disease specialist at the University of California, San Francisco Medical School. He studies the impact of vaccine passports to fight the evolving coronavirus. 



Related Videos