Vaccination is the administration o

Vaccination is the administration 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. Smallpix was the first disease people tried to prevent by purposely inoculating themselves with other types of infections.