She first injects a sample of "wild virus"-- in this case, H1N1 virus shegot from the CDC, originally culled from a child who was infected in California this spring -- and then injects a sample of another flu strain that's known for its ability to rapidly multiply in eggs.
When John started preschool, Ms. Rudnicki says shegot "deer-in-headlights looks" from other parents and teachers because her son was the only child with allergies.