Immunity in children

[Giorgio C. Cosentino]

Karl and Joe,

	You are too generous with your hints.  Children are protected by maternal IgG 
for up to about one year.  The pentameric IgM does not cross the placenta.  The 
antibodies are transported across the placenta during the last 1-2 months of pregnancy. 
This means that a full-term infant will have the same antibody profile as it's mother.  
Assuming that the mother has antibody to childhood diseases (by vaccination or 
exposure), the immunity conferred should suffice in affording protection against these 
diseases.  This protection is waning--by 9 months, the protection would be getting low.
The immune system is quite complex, so I am sure that some other individuals out there 
will have something else to add to this.  Keep the questions coming--it is a good way to 
stay on top of things.

Giorgio Cosentino
giorgio1 at hooked.net