Final answer:
Infants receive passive immunity from their mothers through the placenta and breast milk, acquiring antibodies like IgG and IgA. However, this protection is temporary and does not lead to the development of the infant's own immunological memory. Therefore, the infant's system will not remember the antigen if it gets infected again in the future.
Step-by-step explanation:
Understanding Passive Immunity in Infants
When it comes to the developing immune system of an infant, one critical aspect is the concept of passive immunity. This type of immunity refers to the transfer of maternal antibodies to the infant, either through the placenta or through breastfeeding. Antibodies such as IgG can cross the placenta, allowing the fetus to benefit from the mother's immune response even before birth. After birth, the infant receives IgA antibodies through breast milk, which provides added protection against pathogens.
However, while passive immunity bestows immediate protection to the infant, it does not lead to the development of immunological memory. The antibodies gained this way are temporary, and as they degrade, the protection wanes. As such, if the infant encounters the same antigen later in life, its immune system will not remember the antigen, and it will have to mount its own active immune response to combat the infection.
Therefore, when addressing the question of whether an infant's system will remember an antigen if it gets infected again, the answer is no. The passed antibodies provide protection but do not contribute to the development of the infant's own immunological memory. This distinction is crucial in understanding how newborns and infants are protected from diseases during the early stages of their lives.