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.
Extinction (neurology) state of a vascular disease. The acute state of the vascular disease usually leads to neglect which then in turn leads to the auditory extinction. The number of lesions causes an additive effect when occurring in combination with a recent damage. When it comes to treating and recognizing the occurrence of auditory extinction most sound can still be perceived with the other ear. The nature of sound, which possess directionality but still fills space, makes it more amenable to misattribution of source location. This is called the ‘prior entry’ effect. This is when a stimulus occurring at an attended location