Earlier quoted context omitted.
There is, actually, antibody test. They are quite costly however. Im my country, getting infected count as the 1rst dose (yes, i know, natural immunity is better with "real" infections, but rememeber that Covid sometime start an auto-immune disease, it's hard to test for this, so its less costly to just vaccinate people (the jab cost 12E)). No scientific response. This is mostly pragmatic, and probably politic too. I…
You can get them for free in the uk https://www.gov.uk/government/publications/coronavirus-covid...
Imagine half the uk population wanted to get tested before getting the vaccine, the cost for the NIH would be way higher than just vaccinating everybody. You can't tell people `if the antibody test is positive, you don't have to get vaccinated`, at least not until the vast majority is already vaccinated. And even then, it's mostly lost money.
You could have told people "pay for your own test", but in this case, the fabrication and distribution of those test would slow down the vaccination. And you have to make sure that the test are not faked, so a doctor should verify that the test was yours. I know some doctors who faked smallpox vaccine, so you can imagine how much of a good idea this is.
Also, even if the individual cost is not that high, telling people to `pay not to get vaccinated` (because it would've been spin like this, I've read UK newspapers) is not the best idea want the biggest issues for most western government is lack of trust.
So: it is more pragmatic to jab everybody. Easier to orchestrate, you don't expose your leadership too much. Overall, best solution for the governments. Is it the best solution for the population? Debatable. I'd say its the most cost-effective, the one with the less headaches, so yes?