I personally do not know anyone who was injured from them
In general, if someone is hurt by the antibodies infusion, it will be chalked up to the Covid, so you would rarely know.
In fact, the immune response is similar to that of a vaccine except that it’s more concentrated than the vaccine so any negative reaction would actually be stronger.
It’s just as untested as the vaccines, so the whole antivax argument goes out the window if the alternative is the more risky MaBs treatment.