What specific antibody level in U/ml is sufficient to protect against reinfection. Please cite your sources with peer reviewed research.
"That is a function of level of exposure, individual immune system response, type and quantity of antibodies present, and which variant the individual is exposed to. In other words, it's entirely situational. However, greater levels of antibodies provide greater levels of protection. If you have 2 antibodies in your whole body, they aren't helping you. If you have 500 billion, they're likely overwhelming any variant and any reasonable level of exposure."