OPV has been the vaccine of choice for controlling poliomyelitis in many countries, and for the global polio eradication initiative, because of the ease of oral administration, its superiority in conferring intestinal immunity in immunologically naive individuals, and its low cost.
Persistent depressive disorder, or PDD, (formerly called dysthymia) is a form of depression that usually continues for at least two years. Affects approximately 1.5 percent of the U.S. population age 18 and older in a given year. (about 3.3 million American adults).
Only 25 percent of adults who experience mental health issues feel that people are sympathetic toward people struggling with mental illness, according to the Centers for Disease Control and Prevention. Depression is a negative view of self, of the world and of the future, Greden explains.