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.
Voluntary Human Extinction Movement higher in the food chain are less important than lower species. His ideology is drawn in part from deep ecology, and he sometimes refers to the Earth as Gaia. He notes that human extinction is unavoidable, and that it is better to become extinct soon to avoid causing the extinction of other animals. The potential for evolution of other organisms is also cited as a benefit. Knight sees abstinence from reproduction as an altruistic choice – a way to prevent involuntary human suffering – and cites the deaths of children from preventable causes as an example of needless suffering. Knight