Bacterial vaccines for the treatment of multiple sclerosis and other autoimmune diseases

In animal models it is often possible to block Th1-mediated autoimmunity by deviating the response to Th2. In this article, Graham Rook and colleagues argue that this might prove a dangerous strategy in humans, and that we sh ould distinguish between potentially pathogenic Th2 effector cells, and Th2 -like physiological regulators of Th1 responses. The regulators might be tr iggered by appropriate Th1-inducing bacterial vaccines.