Читать книгу Vaccines For Dummies - Sharon Perkins - Страница 34

Smallpox is the only human virus that humans have ever eradicated. There were two different variants. The more dangerous version would kill 30 percent of those infected and leave survivors with scars, frequently on their faces.

This virus led to the first inoculations with bits of material from smallpox skin lesions. These date back to at least the tenth century BC in China. The virus was so bad that it seemed better to be injected with a small amount and have a mild infection with some risk than to have a severe infection later with greater risk of dying. It also inspired the first vaccine, using cowpox to create a mild infection that protected against smallpox in 1796. (See Chapter 5 for more on the development of the smallpox vaccine.)

The World Health Organization, a little under 200 years later, building on the success of the vaccine, led a large campaign to vaccinate and track down every last case until they finally succeeded in 1977. In the last 100 years before it was eradicated, variola is thought to have killed 500 million people. There was one last death from smallpox after it had been eradicated, a visitor to a laboratory where it was still studied. After this occurred, stocks of smallpox virus were destroyed around the world. Only the United States and Russia are known to have kept stocks in laboratories.

The upper arms of those who were vaccinated for smallpox have a small scar that shows they were vaccinated. Vaccination was stopped in 1972 in the United States, after the disease was eliminated from the United States. By 1980, vaccination had stopped worldwide. It just wasn’t needed anymore, but some people, those who work in labs with the virus or military personnel, may still be vaccinated because there is concern about bioterrorism from this virus.