Look at the maturation of the immune system in neonates - particularly with
regard to the ability to produce different subclasses of IgG. Protection
against some infections depends on specific subclasses of IgG (IgG2, if
memory serves me) - infections including Haemophilus influenzae, E. coli -
there's a recognised group and any medical microbiology text should identify
it. The class of antibody is somehow related to the type of antigen involved
in the immune response.
In more general terms, any infant animal will be more prone to develop
infections (including subclinical ones) as it encounters them for the first
time. This will be influenced by the level of herd immunity. The juvenile
animal has already had some of the infections and is less likely to
encounter new ones.
GS
L.A. Pike-Nobile wrote in message ...
>>Well, you've got to consider at least two factors here: the immunity
>received from nursing is mostly _passive_ immunity (although there is a
>cellular component in breast milk, I think it's general agreed that
>maternal antibodies are critical.
>>Nursing certainly does not transfer all immunities--only those to which
>the mother has circulating antibodies. Admittedly, these are likely to be
>highly relevant. Moreover, maternal Ig does not reflect what the infant
>may uniquely exposed to (this is not common, although kids in daycare
>probably come in contact with things their mothers have no exposure
>to--until their child infects them :).
>>One of the more common defects in newborns is a transient inability to
>produce their own antibodies in the first several months of life, putting
>them at higher risk as antibodies they're revceived in utero and in lacto
>have been catabolized (30-90 days).
>>The other thing to consider is that a neonate's neutrophils (aka PMNs or
>leukocytes) are markedly less functional and at lower numbers (I
>believe). These guys really represents the first line of defense after
>the skin and handle the primary response to many external threats.
>>So I'd say your instructor is right on this one. But, as a grad student, I
>assume I've missed something critical that someone will helpfully point
>out.
>>-Larry
>>>On 7 Mar 1998, FLOIAM wrote:
>>> I need an answer!! I am an undergraduate student and recently had a
discussion
>> with my instructor over the neonates natural immunity. My instructor is
of the
>> opinion a neonate is at much higher risk to infection than say a toddler.
I on
>> the other end of the spectrum am under the impression that a breast feed
>> neonate's immune system is as good or as bad as it's mother's. Someone
please
>> clarify. Any information/articles would be appreciated.
>>>>>
