By Elizabeth Cohen CNN Senior Medical Correspondent (CNN) – Next week, the long-awaited H1N1 vaccine is expected to arrive. At least three of the four vaccine makers have begun shipping their products to undisclosed distribution centers. [cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2009/HEALTH/09/30/h1n1.vaccine.decision/art.h1n1.vaccine.csl.gi.jpg caption="Clinical trials to test the effectiveness and safety of the H1N1 vaccine have been under way … Continue reading What you need to know about the H1N1 vaccine