<unk>  is the administration of agent-specific, but relatively harmless, antigenic components that can induce protective immunity against the corresponding infectious agent in those individuals who are vaccinated. In practice, the terms<unk>  and immunization are often used interchangeably.<unk>  is highly effective in the prevention of some particular infections. Vaccines are safe and are associated with minimal adverse reactions.<unk>  can prevent illness, disability, and death from vaccine-preventable diseases, which includes cervical cancer, diphtheria, hepatitis B, measles, mumps, pertussis, pneumonia, polio, rotavirus diarrhea, rubella, and tetanus. Vaccines help develop immunity by imitating an infection. This type of infection, however, does not cause illness, though it does cause the immune system to produce T-lymphocytes and antibodies. Immunization currently prevents an estimated 2 to 3 million deaths every year. An additional 1.5 million deaths could be avoided, however, if global<unk>  coverage is improved. An estimated 19.4 million infants worldwide are still missing out on basic vaccines. The material administered as a vaccine 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.
Benjamin Jesty is notable for being perhaps the first person recorded to have been vaccinated with cowpox in order to artificially induce immunity to smallpox during the epidemic of 1774. The term<unk>  was first used by Edward Jenner, an English physician, 22 years later in 1796. Louis Pasteur further adapted this principle in his pioneering work in microbiology.<unk>  (vacca in latin means cow) is so named because the first vaccine was derived from a virus affecting cows—the relatively benign cowpox virus, which provides a degree of immunity to smallpox, a contagious and deadly disease. The World Health Organization coordinated the global effort to eradicate smallpox. The last naturally occurring case of smallpox occurred in Somalia in 1977.
Vaccination
Prophylaxis
Education
Screening 
Post-exposure prophylaxis
Nutritional screening and assessment
Cancer vaccine
Traveller vaccination