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Back in the 1960s, the U.S. started vaccinating kids for measles. As expected, children stopped getting measles.

But something else happened.

Childhood deaths from all infectious diseases plummeted. Even deaths from diseases like pneumonia and diarrhea were cut by half.

“So it’s really been a mystery — why do children stop dying at such high rates from all these different infections following introduction of the measles vaccine,” says Michael Mina, a postdoc in biology at Princeton University and a medical student at Emory University.

Scientists Crack A 50-Year-Old Mystery About The Measles Vaccine

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