Originally Posted by LuckyR
If your bolded statement was correct, then I certainly hope you are not arguing that random citizens without specialty training in the subject involved have superior expertise when compared to those who do. Or to put it another way, whatever the bias involved in University research, and I agree with you that it is not zero, certainly the bias/error of random Tennis Warehouse posters is at least an order of magnitude greater.
As to the rest of your post, I'll use your nomenclature:
If you have 500 antibodies available to you right now, it is because of the 900 total antibodies you have, 400 are being used for various random antigens that enter your body all day, every single day from an infinite number of sources. True, you could use 5 of the 500 to deal with your flu shot (and increase the number being used to 405), but the benefit that the corrupt and money-driven evil Pharma Empire tricks us into thinking exists is felt to be worth that limited drop. Remember antibodies by their nature are extremely specific, that's why it is ridiculous to suppose that some high percentage of your antibodies would respond to a single exposure. For example, your chickenpox antibodies don't care if you are exposed to a cold sore, different virus, different antibodies.
To add to this, antibodies are not even produced until T&B cells contact the foreign antigen. Theoretically, for every antigen there is a T cell and a B cell that fit it like a lock & key.
Once an antigen (say the flu vaccine) enters your body and matches up with the correct T&B cell then an immune response is mounted. One aspect of that immune response among others is the production of antibodies by B cells. Thus antibodies are not even produced until exposure to that given antigen.
As LuckyR said, an antibody is specific to a given antigen. That is, a certain antibody can't be used to fight anything else besides the antigen that led to its production. Therefore, at least in theory, the flu vaccine doesn't hinder an individuals immune response to other antigens.