Darillyn asks whether there are known risks to children in developing countries in connection with weaning and the answer is yes. Called 'sibling syndrome' or 'sibling disease', it is well known among health workers in developing countries and occurs when a young child loses access to breastmilk because mother has had a new baby. The older child is more vulnerable to infection due to the loss of 1) a clean source of a very nutritious food and 2) the passive immunity conferred through breastmilk. While infants during the early months absorb maternal antibodies present in milk, through the gut mucosa, these antibodies continue to play a significant role in infection protection after the gut mucosa becomes impermeable to these large molecules. The antibodies attach to the cells lining the gut, and act locally to fight microorganisms that otherwise cause diarrhea. The same mechanism in the upper airway protects against respiratory infection. There is a noticeable increase in child mortality due to infection among children who have recently become big brothers or sisters. Even in cases where the child's growth may already have been faltering due to lack of appropriate and/or available weaning foods, as long as the breastmilk is available they generally do not fall prey to the most common infections. This changes radically when they are weaned to make room at the breast for a sibling. In conditions of marginal nutrition, women don't get pregnant as readily while breastfeeding, which prioritizes the child already born. Once the mother does get pregnant, her milk supply may dwindle or there may simply not be enough calories around after birth to supply milk to both the infant and the older sib. Even when the infants are absorbing maternal antibodies into their bloodstream, it is considered passive immunity because the antibodies are not manufactured by the infant. I don't believe that exposure to antibodies 'teaches' the infant's immune system to produce endogenous ones; it may be that the protection offered by maternal antibodies gives the infant a safety cushion, protecting the infant while its immune system matures and begins producing its own antibodies as a result of exposure to minute amounts of antigens while still being 'covered' by breastmilk. Rachel Myr Kristiansand, Norway *********************************************** To temporarily stop your subscription: set lactnet nomail To start it again: set lactnet mail (or digest) To unsubscribe: unsubscribe lactnet All commands go to [log in to unmask] The LACTNET mailing list is powered by L-Soft's renowned LISTSERV(R) list management software together with L-Soft's LSMTP(R) mailer for lightning fast mail delivery. For more information, go to: http://www.lsoft.com/LISTSERV-powered.html