Since the adoption of mass vaccination programs, many diseases have been curbed. [[Smallpox]], a deadly disease responsible for the deaths of millions, has been entirely eliminated through vaccination, excepting some strains maintained for research. Responsible for an estimated 300 to 500 million deaths worldwide in the 20th century, vaccination programs of the 19th and 20th century were effective at curbing the disease, and in 1979 the World Health Organization declared smallpox to be eradicated. | Since the adoption of mass vaccination programs, many diseases have been curbed. [[Smallpox]], a deadly disease responsible for the deaths of millions, has been entirely eliminated through vaccination, excepting some strains maintained for research. Responsible for an estimated 300 to 500 million deaths worldwide in the 20th century, vaccination programs of the 19th and 20th century were effective at curbing the disease, and in 1979 the World Health Organization declared smallpox to be eradicated. |