Microsoft founder Bill Gates, his wife Melinda French Gates and British Prime Minister David Cameron at the World Economic Forum on January 28, 2011, in Davos, Switzerland. Johannes Eisele/AFP/Getty Images hide caption

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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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Antibiotics Defeat Ear Infections In Young Kids, Studies Find
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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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To Beat Chickenpox, 2 Shots Of Vaccine Are Best
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Study Linking Childhood Vaccine And Autism Was Fraudulent
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