antibody - (Jan/07/2007 )

Antibodies that the body builds against some killed microorganisms may also be effective against live microorganisms. I don't really understand that. Do antibodies need to attack the microorganisms that had already been killed? killed microorganisms still harm our body? Antibodies need to kill killed microorganisms and live microorganism?
Thanks for help.

ok...
this is how you obtain the antibodies...
when you inject a rabbit for example with killed microorganism, the immune system of rabbit will respond by producing specific antibodies to the antigen (killed micro.)..you can take a blood sample, test it and obtain these antibodies for future use....this is it

so when rabbits or other organisms became infected with that microorganism (living)..you can simply use the antibodies you already have..

hope this clear the picture..
i recommend you to read more from books, web-sites, etc..don't rely one source

Just a little bit addition, antibodies don't recognize their 'enemy' by living or dead, but by the protein that construct their enemy's body. Both living or dead things are harmful to our body. Living things e.g. bacteria, virus, parasites, will destroy our body system, while dead things e.g. debris and dead cells will be a waste inside our body. By recognizing the protein from dead things is enough to recognize those things while still alive, because protein is specific.

Sorry my English might sound weird. Hopefully you understand

so the antibody is able to recognize a protein, from dead or alive bacteria. It will recognize it the same. It's like if you would recognize the T-shirt of a guy , dead or alive.
the benefit to recognize a live bacteria will be that the binding of the antibody on the bacteria will able other proteins to bind on the complex formed by the antigen/antibody, leading to the formation of a pore inside the membrane of the bacteria, and the death of the bacteria (complement activation)

the benefit to recognize a protein of a dead bacteria will be to inactivate a toxin for example. if a huge antibody binds to the toxin, the toxin will not be able to bind to its receptor or ligand anymore, and will not be able to produce bad effects on the infested host.