Constitution rolls to resist diseases or infections are at -1D. The Panimmunity advantage or panimmunity treatment will have half the normal effect. Unless you take special precautions (remain in a sealed environment or wear air-tight clothing when you leave one) the GM should require an Easy Constitution roll every month to avoid coming down with a potentially serious illness. Although not necessarily fatal, this will take you out of the action and force you to spend additional money on drugs and hospital treatment.