I would not do it this way. I use a Virus neutrlizing technique which works on a Quantum Basis energetically. All viruses in the Body are neutralizied within a few minutes. After the Treatment the Person is fre from infective Virus particles. He is no longer a danger for other People and he himself is immune for reinfection. I haved done this also to myself.
So what? for treating Virus infections you do not Need medication and you do not Need vaccines and also no strange antibodies weher you never know what thexy do. You make an artificial autoimmunreaction. This cannot be a good way.
Reinfection has been seen in some patients of covid-19 so antiserum might not be useful . I suggest read about the trials of using NK cells in serious covid-19 patients by dr Casper (fda approved)