This is a scary dystopian prospect with the sole purpose of separation of classes and limiting undesirables. I think the author hasn't traveled much and doesn'

This is a scary dystopian prospect with the sole purpose of separation of classes and limiting undesirables. I think the author hasn't traveled much and doesn't understand the yellow card. Countries which require you to have one, it's only required if you've come from a country that's listed as having yellow fever. When you look at how they're used in practice it's countries using it to lock out other countries. They are a black market commodity. Yellow fever is far more worrisome than covid19. Yet having traveled to several African countries that require it I was never asked once. Upon return to the US again no one cares even though I was clearly in yellow fever areas. The WHO does not recommend travel bans for disease spread prevention. It also doesn't recommend this kind of immunity passport. So why are you trying to compare a yellow card to this?