Ottawa physician Barry Dworkin, who practices obstetrics and adolescent medicine, believes the backlash against vaccines due to fears that the shots may weaken the immune system and cause serious adverse effects is based on misinformation. Dworkin recommends that parents discuss any vaccine-related concerns with their family doctor and become informed about childhood diseases. He notes that although vaccines are not 100 percent effective in all cases, "our goal as parents is to protect our children from harm," and the evidence in favor of vaccination programs is significant.