Absolutely not. Not every jabbed develop antibodies at all and most jabbed loose antibodies fast (this is one of their reasons for permanent boosters or revaccinations bullshit). Also antibodies could present in never jabbed due to previous contractions from illnesses, or as response to contact with pathogens in small quantities not enough to develop an illness. So antibodies can't be a definitive marker of vaccination with SputnikV/AstraZeneca, especially in the span of declared six months of "protection".

Also, it is explicitly stated in docs on SputnikV that all components are go out of body very fast, and that is one of the main reasons in claims about vaccine safety.

Usually, substances that could last long in body used as markers. mostly different isotopes that used by body as ordinary elements for bulding body cells or bones or other parts. Such markers could stay in body and be detectable for years. Also, some elements could accumulate in different organs, but that is usually harmful for humans and especially harmful if you constantly add them. But it will be hard to distinguish if they accumulate from vaccine or other sources. Few organic substances could accumulate in liver, f.e. but they are harmfull and not distiguiseable from other sources too. Complex organic substances injected with vaccine that could possibly confidently prove a jab usually go out of body or breaked up as fast as possible, as their traces.

Also he specifically told about some unknown for public "specific test for that markers", and not usual antibodies test.

In any case, independent of what they mean under "markers", statement about markers completely contradicts with earlier statements or official documentation. Or he just lie about markers to cover complete vaccine inefficiency.