Merck & Co. has received FDA approval for Rotateq, the only vaccine available in the U.S. to prevent rotavirus gastroenteritis, a leading cause of severe diarrhea in infants and young children. Rotateq is an oral, three-dose vaccine given to infants between the ages of six to 32 weeks. The FDA approval of Rotateq is based on data from the company’s Phase III trials of more than 70,000 infants, including the Rotavirus Efficacy and Safety Trial (REST). Among infants observed, Rotate...