With H1N1 vaccine shortage expected, highest-risk groups go to front of line.  Who is at risk for serious infections and why?
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006282:Health Personnel; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage*; D007251:Influenza, Human / Q000276:immunology / Q000517:prevention & control*; D011247:Pregnancy; D012307:Risk Factors
D007252:Influenza Vaccines