It’s a new twist on an age-old question: What came first, the chicken or the fertilized egg?
So far as flu vaccine production is concerned, the answer is definitely the egg. Millions of contaminant-free, fertilized eggs are needed each year to produce vaccines against predicted strains of influenza. Absent sufficient numbers of â??cleanâ? fertilized eggs, there is no current way to produce the flu vaccines public health experts believe we’re most likely to need.