The Food and Drug Administration said preliminary results from a study in Mexico involving GlaxoSmithKline's Rotarix vaccine suggest an increased risk of a serious bowel problem that could be fatal.
A statement posted to the FDA's website said the study showed an increased risk of intussusception in the 31-day period following the first dose of Rotarix. Intussusception is a twisting or obstruction of the intestine that can be fatal.