mark wrote in message <36CB6660.3AA8 at mail.tju.edu>...
>aureus wrote:
>>>> This disease is cripiling to adults who donot possess immunity to the
toxin.
>> Immunity is a passive aquired method of weaken toxoid injected into the
>> body. Immunity usually occurs within a couple of months (IgG). The
>> antibody will not be transferred prenatally or cannot be transferred from
>> human to human.
>>>I 'm confused (and no its not the 1st time). Arew you saying that igg
>isn't transferred transplacentally? If so i disagree. Whether it is
>also transferred in breast milk is something i'm not sure of although i'm
>pretty sure that iga is in natural milk. Am i wrong?
>markH
If mother has been immunised then baby will have IgG antibody from mother's
circulation; but this antibody is eventually broken down and by about 6
months of age there will not be much protection left. Since the immune
system is immature at birth, babies don't have the capacity to respond to
all antigens (which is why some bugs are more dangerous for very young
babies). In any case, clostridia toxins can be damaging (or even fatal)
below the level at which they can stimulate an immune response. Catch 22 -
if you try to immunise baby too early, mother's antibody may mop up the
vaccine and reduce or even prevent the stimlation of the baby's system.
Toxoid is an inactivated form of the toxin which is able to produce an
immune response but which is non-toxic. This is active immunity (passive is
when you give anti-toxin - antibodies from a donor - which will also be
broken down and will not give long-lasting protection). IgA is probably not
so important in tetanus - it mainly acts at mucosal surfaces, eg the gut; so
transfer of this antibody in milk is an efficient way of transferring
protection to the infant.
GS
