What defines a healthy immune system?? Is it labs that indicate a good red, white and platelet count? Is it fighting off colds and flus properly and/or not getting sick much at all? I wonder this as a young person who has been chronically fatigued since my flu shot (in Nov. 2002) and as a person who has had normal labs since my innoculation. On this board there obviously is talk of immune suppression and immunal compromised individuals. I am wondering what this all means. Thank you-this website has been wonderful.