Officials track down pandemic flu samples.
Stephenson
Joan
J
D002487:Centers for Disease Control and Prevention, U.S.; D003140:Communicable Disease Control; D004196:Disease Outbreaks / Q000517:prevention & control; D006801:Humans; D009980:Influenza A virus; D007251:Influenza, Human / Q000517:prevention & control; D007753:Laboratories; D014481:United States