Previously, it was generally thought that immunity against illness is passed from mum to baby for only the period they are breastfed and this protection ends when breastfeeding stops. It was also thought that this immunity was transferred by a mother’s proteins such as antibodies that are used by the immune system to neutralize bacteria and viruses.
However, research in mice by scientists published in Science Advances, has found that the transfer of immunity can be long-term, beyond the period of breastfeeding. They also found that this protection was driven by the transfer of immune cells and was completely independent of antibodies. The research found that infant mice breastfed by a mother who had a worm infection before becoming pregnant acquired life-long protection against this infection (worm infection).
Unexpectedly, this effect was passed onto the infants by cells in the mother’s milk and not proteins such as antibodies, as it was formerly known. These transferred cells provided protection from worm infection throughout the body to the infant. This work shows that mothers exposed, even before pregnancy, to a globally prevalent source of infection provides long-term breastfeeding-acquired immunity to infection in their infants.
The work shows that exposure to an infection before pregnancy can lead to a mother transferring long term immune benefits to her offspring.