Presumably proving 100% efficacy is impossible. Among other things, there are immune disorders that ensure you're still at risk even if fully vaccinated. And an

Presumably proving 100% efficacy is impossible. Among other things, there are immune disorders that ensure you're still at risk even if fully vaccinated. And anyone is at risk with a depressed immune system, which can be caused by sleep, diet, stress, unrelated illness, pregnancy, etc etc. and finally remember that vaccinated people still get infected, they just are able to fight the infection with high success rate (you claim 100% but 3% is a big gap to explain away). Even people who successfully fight the infection completely unsymptomatically likely incur a cost to their organs and immune system as a result. Even with vaccinations, you should attempt to avoid risk of infection if you can.