This kind of illogical policy gives fuel to antivaxers.
Also, this article provides some arguments based more on biology. https://arstechnica.com/science/2021/10/prior-infection-vs-v...
There is such a thing as testing for neutralizing antibodies by testing the antibodies against the virus directly. But in general, all of the relevant tests seem to be more expensive and harder to standardize.
Every human body creates its own set of antibodies against the virus (or the vaccine). Starting from different strains of the virus, the potential for uncertainty is too great.
Too great for what? Even with 2 jabs, the immunity is <90% against Delta and research shows post-covid immunity is more effective.
Not OP, but if arguing against it is anti-vaxx, then I guess you should call me anti-vaxx and I'll call you unreasonable.
Anti-vaxers hate all vaccines. Most of this thread is about following actual science and practices used for other vaccines. If you've had it, then don't get the vaccine, otherwise get the vaccine.
And those who argue the most don't really argue about "they don't need the vaccine", but rather assume the vaccine is much bigger risk or damage than is at all reasonable. And that, yes, puts you very close to the "anti-vaxx" bubble.