If the "gulf war cocktail" contains antibodies, it is not really a
vaccine.  Injection of antibodies gives passive immunity, unlike a
vaccine which is supposed to stimulate *active* immunity.

If only antibodies are in the cocktail, there is no concern, because
normally, the usual antibodies do not pass into the milk from the
mother.  Only very very small amounts of IgG (the likely antibody
given), IgE, IgM and IgD appear in the milk.  Most would be destroyed in
the nursling's stomach.  Only SIgA gets into the milk in significant
amounts because it has a *secretory* component which allows it to do so.
No other antibody does.  Furthermore, it also has a "J" chain which
protects it against digestion in the gut.

If there are killed bacteria in the cocktail, the former cannot do
anything, and besides probably won't get into the milk anyway.  The baby
will be protected by his mother's nursing.

Toxoids (weakened toxins), like all large proteins, will not get into
the milk.  Furthermore, the majority have no effect when taken by mouth.

If a combination, same argument.

Jack Newman, MD, FRCPC