Antibodies are not immunity, with viruses, coz viruses spend most of their time INSIDE cells. Archived Message Posted by Shyaku on October 28, 2020, 5:23 pm, in reply to "Antibody levels" Many or even most viruses have a very brief extracellular phase. So brief exposure to antibodies during their lifecycle. This obviously contrasts with bacteria and parasites, which do not enter our cells. During the extracellular phase, viruses have ways of escaping the immune system, via conformational effects, steric effects, or mutation, or a wrapping membrane, etc. So antibodies are a test of *exposure* for sure. But actual immunity in large or dominant measure comes from the innate immune system (complement, phagocytosis) and from the cel-mediated arm of the adaptive immune system, not so much from the antibody arm. The cell mediated arm causes cells that CONTAIN viruses to commit suicide. This is a powerful mechanism for a vaccine to stimulate if possible. - Shyaku Message Thread: Antibody levels - Mary October 27, 2020, 5:14 am Re: Antibody levels - Alan Haynes October 27, 2020, 8:10 am Re: Antibody levels - dan October 27, 2020, 11:21 am Re: Antibody levels - dan October 27, 2020, 11:28 am Re: Antibody levels - Alan Haynes October 27, 2020, 12:07 pm Re: Antibody levels - Mary October 27, 2020, 12:32 pm Re: Antibody levels - dan October 27, 2020, 7:27 pm Antibodies are not immunity, with viruses, coz viruses spend most of their time INSIDE cells. - Shyaku October 28, 2020, 5:23 pm   Searching