According to my healthcare provider, a newborn should not be affected by chicken pox if it has immunity thanks to his mother having had the infection as a child herself - this immunity is apparently womb gained and lasts roughly a year. Let's assume that the infant is also breastfed exclusively - apparently, this assists the immunity because the mother's milk contains antibodies the newborn can use for resistance to various infections.
It seems like there is thus a mechanism where antibodies can be acquired from the mother and used by an infant to fight a disease. I'm told that breastfed babies do not get sick as often as formula fed ones, because disease the mother is exposed to causes antibodies to pass from the mother to the baby in the breast milk.
is it true? I've only received this information anecdotally from midwives, but has it been subject to scientific scrutiny? Are the mechanisms well understood? (It seems unlikely to me that eating someone else's antibodies helps a person fight disease; why are the antibodies not digested and decomposed?)
if true, does the newborn develop his own immunity from his own immune system, while it uses the mother's antibodies to fend off the chickenpox? Or does it replace his defence mechanism for a while (e.g the first year of life) to let him grow strong, but he will remain liable to contract illnesses like chickenpox later?
if I, as an adult who has never had chickenpox myself, were to consume the breastmilk would I also benefit from enhanced resistance to chickenpox or other diseases the producer is exposed to/can generate antibodies for? Or is this antibody transfer mechanism limited to mother and child?