Schools in Grayville, Ill., closed on Monday, and won’t reopen until Thursday [1], after more than 20 percent of the town’s elementary through high school kids came down with the flu, the Huffington Post reports. From Minnesota [2] to Oklahoma [3], schools have made similar decisions, while workplaces, hospitals, churches and sports teams are taking their own precautions in the face of what is likely the worst flu season in more than a decade. When the flu strikes, kids tend to be the first sick due to their lower immunity and more frequent contact with others — including the natural intermingling at crowded schools. In a study published in October, Dr. Marty Cetron of the U.S. Centers for Disease Control and Prevention, who has three kids of his own, and fellow researchers evaluated the approaches taken by two Texas school districts’ during the 2009 H1N1 pandemic [4]. One district temporarily closed schools early in the outbreak, while the other kept doors open throughout. Cetron said the differences were “profound,” including fewer self-reported emergency visits and influenza-like illness in areas where schools had closed, even if only for a week or so. The benefits also extended beyond the students to entire communities…