Question

When considering immunity in babies, the main mechanism that supports their undeveloped immune system is the transfer of antibodies from mother to baby via breastfeeding.

Case 1: both baby and mother got sick with a virus; the mother then produces large amounts of antibodies that are passed to her baby via breastfeeding.

Case 2: just the baby got sick.

What are the possible scenarios for supporting the baby's immune system in that case?

Answer 1

In Case 2 where only the baby gets sick, the infant relies on passive immunity from antibodies such as Secretory IgA in breast milk and IgG from the placenta that the mother has previously transferred to combat the infection.

Step-by-step explanation:

When a baby gets sick and the mother is healthy, the baby can still benefit from the passive immunity offered through breastfeeding. The antibodies produced in the mother's body, specifically Secretory IgA that are present in breast milk, can help to protect the baby by directly combating pathogens in the baby's system.

Additionally, the transference of IgG antibodies through the placenta during pregnancy already provides the baby with a degree of immunity at birth. Case 2, where only the baby falls ill, the support to the baby's immune system comes from these antibodies that were already passed from the mother, which remain in the infant's body for some time, providing protection and fighting off the infection.