immunity passports

As we try to reopen our domestic and global markets, as well as entertainment venues, increasingly there are voices calling for a method to ensure safe passage. That method is a so-called immunity or vaccine passport. But each comes with its own price – and ethical problems.
Where does the 2600 tons of oxygen we use daily in the hospitals come from? Not all creatures have a microbiome, what is up with that? Why are lies and misinformation so resilient? And two lessons from history, one about where we shelter, the other about "travel papers."