ABSTRACT
The immune system, just like the endocrine and neural systems, is a major inducible biological response system. Its function is to protect the host against pathogenic attack. Nowhere during our entire lifespan are we subjected to more foreign antigenic stimuli for the first time than during the early neonatal period, when the newborn passes from the relatively protected environment of the womb to the hostile world of pathogens. The newborn’s immune defense system is therefore a vital response mechanism essential for its protection in the new environment in which it finds itself.
