SWINE FLU UPDATE: Flu Has a History of Foreshocks. “In past decades, a smaller influenza wave has preceded pandemics, but experts say there is no way to predict if H1N1 is such a precursor. . . . Scientists think the spring swine flu epidemic may be a ‘herald wave’ of what’s to come. In 1918, a milder wave of flu cases occurred in late winter and early spring, before the deadly pandemic surge in the fall of that year. In 1957, Asian flu was causing unremarkable illness in China, before landing on American soil for the summer outbreaks and a severe winter season.”