Swine flu has now hit as many as one million Americans, U.S. health officials report—and in some areas, 6 percent or more of urban populations are affected. The estimate was reached through mathematical modeling, based on surveys from health officials. The U.S. represents roughly half the world's swine-flu cases, with nearly 28,000 reported to the CDC so far—these cases include 3,065 hospitalizations and 127 deaths. The percentage of cases hospitalized has been growing, though health officials point out that this trend may be due to closer scrutiny of very sick patients. Keeping it all in perspective, however: Regular seasonal flu sickens anywhere from 15 million to 60 million Americans each year. Also, a vaccine for H1N1 may be on the way.