Surely babies have some sort of immune system happening before 6 months???? I know the immune system is a very complex thing, but that just seems wrong to me, that they have none????
Im sorry, i probably should have said they have an 'undeveloped' immune system.

Just like the lungs on a premature baby, they dont function 100% until they are full term

The immune system is similar, its there but it doesnt begin to function until a certain age (approx 6months)

All the babies antibodies come from the mothers milk in the early stages.