For decades, Merck misrepresented the efficacy of its mumps vaccine, marketing an “adulterated” drug without proven efficacy to millions of American children, according to a recently released expert report by Dr. David Kessler, former head of the FDA.

For decades, Merck misrepresented the efficacy of its mumps vaccine, marketing an “adulterated” drug without proven efficacy to millions of American children, according to a recently released expert report by Dr. David Kessler, former head of the U.S. Food and Drug Administration (FDA).