Like I said, some people, no matter how many times they have a vaccine pumped into them will not create the antibodies.
In the last 15 years, every year, I have had HepC vaccine pumped into me, 2 doses same as the COVID and 18 days a apart (IIRC). I have an antibody test after the first and again after the second jab and both show negative every time, very year. The quack told me that I am not alone. Many people for whatever reason are unable to produce antibodies after a vaccine, almost any vaccine.
I have the flu vaccine every year but I've no idea if I have the antibodies or not because I've never had an antibody test. I haven't caught the flu (the real flu, not just a bad cold) but I've no idea whether it's just luck and the immunisation that's kept it at bay.
It's too early to tell what the effects of the CV vaccine will be until there are large scale antibody tests. That's why we will require continued testing.