Pandemic smallpox was responsible for 300–500 million deaths. As recently as the early 1950s, an estimated 50 million cases of smallpox occurred in the world each year. After successful vaccination campaigns throughout the 19th and 20th centuries, the WHO certified the eradication of smallpox in December 1979. To this day, smallpox is the only human infectious disease to have been completely eradicated, and one of two infectious viruses ever to be eradicated. Historically, measles was prevalent throughout the world, as it is highly contagious. According to the U.S. National Immunization Program, 90% of people were infected with measles by age 15.
Dracunculiasis Guinea worm-free. The results of this certification scheme have been remarkable: by 2017, 15 formerly endemic countries—Benin, Burkina Faso, Cameroon, Central African Republic, Cote d'lvoire, Ghana, India, Mauritania, Niger, Nigeria, Pakistan, Senegal, Togo, Uganda and Yemen—were certified to have eradicated the disease. In 2017, 30 human cases were reported — 15 in Chad and 15 in Ethiopia; 13 of which were fully contained. For the first time ever, South Sudan reported no human infections for a whole calendar year: the last reported case was on 20 November 2016. No human cases were reported in Mali for the second year in