A student at Carlin Springs Elementary School receives a flu shot last January in Arlington, Va. Mandel Ngan/AFP/Getty Images hide caption

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Antonio Garcia re-stocks the beverages at The Corner Market in Washington, D.C., in 2010. Study author Jean Welsh says that sweetened beverages tend to be the biggest source of added sugar. Jacquelyn Martin/AP hide caption

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A study that measured antibodies and the disease history of more than  200 kids found that two doses of vaccine were 98 percent effective in  preventing chickenpox compared with 86 percent for a single dose. AP hide caption

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