During the 1980s and 1990s, a number of lawsuits were brought against manufacturers of vaccines, alleging the vaccines had caused physical and mental disorders in children. While these lawsuits were unsuccessful, they did lead to a large jump in the costs of the MMR vaccine, and pharmaceutical companies sought legislative protections. In 1993, Merck KGaA became the only company willing to sell MMR vaccines in the United States and the United Kingdom.