[danarmak]

The immune system presumably has a limited capacity of circulating antibodies. By introducing new antibodies, do we reduce the amount of previous antibodies, and does this reduce their immune response? Is there a concept or metric of "antibody dilution"?

[Retric]

Antibody production ramps up and down rapidly, it’s memory cells that get altered by vaccines. https://en.wikipedia.org/wiki/Immunological_memory

That said the immune system is extremely complex, but here is a simplified version, which gives a reasonable overview: https://microbenotes.com/cells-of-the-immune-system/

[dannyw]

While correlation is not causation, I find it interesting that the human immune system only remembers the common cold and seasonal influenza for several months, but diseases like the polio for much longer.

https://biology.stackexchange.com/a/21802

[TylerE]

"The common cold" is a loose nebula of hundreds of different, unrelated, virus strains. They're not even all the same TYPE of virus.