Dear Annette,

Whooping cough is *very* dangerous in infants under 6 months. Exposure of
unvaccinated infants should be taken very seriously as there is an
associated risk of mortality.  Immunizing early will not remove the risk.
Even a full immunization schedule does not offer full protection (although
the risk of both complications and epidemics is markedly reduced).

There are AAP guidelines for chemoprophylaxis of immediate contacts, I
believe the recommendation is erythromycin 30-40 mg/kg/day in 3-4 divided
doses for 2 weeks.  The index case should also be on treatment.  This
protocol should be confirmed by your local department of health as they
only do it for *confirmed* cases.

I hope that this helps

Khalid

Khalid Aziz
Memorial University of Newfoundland