Why aren't all a mother's antibodies passed on to the offspring?

Question

What advantage does it give the child to have him or her get sick and build up antibodies themself?

Even after being breastfed. THANKS!

Answer 1

Memory cells allow the child to fight infection more efficiently upon subsequent encounters with a pathogen. A mother's antigens do not allow the child to create these memory t-cells. Also, remeber that breast feeding only provides significant amount of antibodies when the mother is producing colostrum and before the infant's gasto-intestinal tract becomes impermeable to larger proteins. The mother's antibody protection therefore will always stop - so the child must develop their own immune system.

Answer 2

Infection problems in the long run would not be solved even if all antibodies were passed to the offspring! The fact is that even those antibodies that are passed from mother to child are only protective for a couple of months simply because they are not self-renewing. Hopefully the child will have developed their own antibodies by the time these wear off; no wonder children are so prone to many illnesses.
There is little difference between antibody crossover from mother to offspring and you getting antibodies passively e.g use of anti-venins. Those antibodies are only good for the duration of their lifespan and will eventually wear off, thus you are not protected anymore. Therefore, there is overwhelming need for offspring to develop their own immune system for both active and lifelong protection.

Answer 3

What brwalker says is mostly right. I would add, however, that the mother doesn't have antibiotics to everything that may ever come along and the child needs to develop it's own strong immune system.

Just consider, for instance, that common cold viruses change to avoid antibiotic resistance all the time. Each person needs his/her own immune system to be on guard against evolving viruses.