Vaccination is the aministration of antigenic material (the Vaccine) to produce immunity to a disease. Vaccines can prevent or ameliorate the effects of infection by a pathogen. It is considered to be the most effective and cost-effective method of preventing infectious diseases. The material administrated can either be live, but weakened forms of pathogens such as bacteria or viruses, killed or inactivated forms of these pathogens, or purified material such as proteins. Smallpox was the first disease people tried to prevent by purposely inoculating themselves with other types of infections; smallpox inoculation was started in China or India before 200 BC. In 1718, Lady Mary Wortley Montague reported that the Turks have a habit of deliberately inoculating themselves with fluid taken from mild cases of smallpox and she inoculated her own children.Before Edward Jenner tested the possibility of using the cowpox vaccine as an immunisation for smallpox in humans in 1796 for the first time, at least six people had done the same several years earlier: a person whose identity is unknown, England, (about 1771), Mrs. Sevel, Germany (about 1772), Mr. Jensen, Germany (about 1770), Benjamin Jesty, England, in 1774, Mrs. Rendall, England (about 1782) and Peter Plett, Germany, in 1791. In 1796 Edward Jenner inoculated using cowpox (a mild relative of the deadly smallpox virus). Pasteur and others built on this.