Suffering from Seasonal Allergies? Here's What Experts Say Works Best Time - October 21, 2022 Gabriele de Vos, M.D., M.S., says immunotherapy may not be effective for some people with allergies because it is difficult to develop individual tests—and therefore treatments—to determine the specific causes of a person's allergy. Dr. de Vos is associate professor of medicine at Einstein and an allergist and immunologist at Jacobi Medical Center.