[dc396]

Someone (including the President of the US) asserting that any vaccine is 100% effective and will prevent someone from "getting infected at all" simply means that individual does not understand how vaccines and infectious diseases caused by viruses work.

[jvickers]

Indeed. My point is that this sets a standard for what is considered 'effective' and if it falls short of that standard, those who say it's 'ineffective' by that unrealistic standard, that is still correct.

Something can be ineffective compared to something else. Such as a COVID vaccine being ineffective compared to some expectations or representations of it.