Antibodies are passed from mother to baby through the placenta during the third trimester (last 3 months of pregnancy). This gives the baby some protection when they are born. The type and amount of antibodies passed to the baby depends on the mother’s own level of immunity.
During birth, bacteria from the mother’s vagina is passed on to the baby. This helps to build the colony of bacteria in the gut that contributes to their immunity.
After birth, more antibodies are passed on to the baby in colostrum and in breast milk. But babies’ immune systems are still not as strong as adults’. Premature babies are at greater risk of infection because their immune systems are even more immature and they haven’t had as many antibodies passed to them from their mothers.
Babies produce their own antibodies every time they are exposed to a virus or germ, but it takes time for this immunity to fully develop.
The passive immunity passed on from the mother at birth also doesn’t last long and will start to decrease in the first few weeks and months after birth.
Picture Credit : Google