You've lost track? The only 100% required vaccine for international travel I'm aware of is yellow fever, which poses an infection fatality risk hundreds or thousands of times higher than Covid.
The Wikipedia data for yellow fever IFR [0] claims that the data are based on "optimally treated patients". The problem in some of the countries where a vaccination certificate is mandatory to enter is that they do not have healthcare infrastructure to adequately treat patients. Somewhere in the past I have seen statistics that during some African yellow-fever outbreaks, 25–50% of those infected perished, which is why states were so insistent on this vaccination specifically.
That doesn't seem at odds with a single order-of-magnitude difference though. Covid IFR in the 0.5% range is also based on more or less optimally treated patients given a developed country's population demographics. There isn't really room for a fatality rate to be "hundreds or thousands of times higher", you run into the 100% fatal bound pretty quickly.
The Covid IFR is not in the 0.5% range, and a few exceptions notwithstanding, the fatality rate tends to be lower in developing countries than the developed world.
US covid deaths are 0.51% of the CDC’s estimated total number of covid cases. The highest (NPR) estimate of US covid deaths is 0.79% of the CDC’s estimated total number of covid cases (which is, itself, not the highest total case estimate). Many studies have estimates in the similar range.
I know the IFR is lower in developing countries, I never meant to imply otherwise.