Two live oral rotavirus vaccines were approved by the US Food and Drug Administration in 2005 and 2008, following large studies of ∼70,000 each in order to address questions about intussusception triggered by a third earlier vaccine. Both new rotavirus vaccines showed almost identical rates of intussusception in vaccine and placebo recipients. These vaccines have been used extensively in the United States with positive results. Efforts are under way to implement these vaccines in developing countries where the need is greatest.