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If the body produces an antibody against a particular disease or toxin it can identify the infection early on and the [[immune system]] can destroy it. Vaccines work by exposing the body to a form of the disease in such a way that it is much less likely cause illness but still allows antibodies to develop. This confers a level of immunity to the person or animal vaccinated.<ref>http://www.howstuffworks.com/immune-system7.htm How stuff works: Antibodies</ref>

If the body produces an antibody against a particular disease or toxin it can identify the infection early on and the [[immune system]] can destroy it. Vaccines work by exposing the body to a form of the disease in such a way that it is much less likely cause illness but still allows antibodies to develop. This confers a level of immunity to the person or animal vaccinated.<ref>http://www.howstuffworks.com/immune-system7.htm How stuff works: Antibodies</ref>

There are five major types of vaccines and they are differentiated by what type of antigen is used. Live attenuated vaccines are created from the actual disease in question, however before injection the [[pathogen]] is [[attenuated]] (weakened) by growing successive generations of the pathogen in poor nutrient conditions. Because they contain live pathogens, it is still possible for these vaccines to cause infection, particularly in imunnocompromised individuals. Inactivated vaccines are created from pathogens that have been killed, usually with [[formaldehyde]]. Toxoid vaccines are created by using toxins produced by the pathogen, these toxins are exposed to heat and/or chemicals such as formaldehyde to inactivate the toxins, but [[antibodies]] that are produced to these deactivated toxins will also protect against the real toxin. Subunit vaccines use pieces of the pathogen in the vaccine. These pieces often consist of unique protein segments that stimulate the production of antibodies. Finally, conjugate vaccines protect against bacteria that are encapsulated in  polysaccharides (complex sugars), which disguise the bacteria, making it hard for the immune system to recognize them. cungugate vaccines overcume this by attaching the sugar to an antigen

There are five major types of vaccines and they are differentiated by what type of antigen is used. Live attenuated vaccines are created from the actual disease in question, however before injection the [[pathogen]] is [[attenuated]] (weakened) by growing successive generations of the pathogen in poor nutrient conditions. Because they contain live pathogens, it is still possible for these vaccines to cause infection, particularly in imunnocompromised individuals. Inactivated vaccines are created from pathogens that have been killed, usually with [[formaldehyde]]. Toxoid vaccines are created by using toxins produced by the pathogen, these toxins are exposed to heat and/or chemicals such as formaldehyde to inactivate the toxins, but [[antibodies]] that are produced to these deactivated toxins will also protect against the real toxin. Subunit vaccines use pieces of the pathogen in the vaccine. These pieces often consist of unique protein segments that stimulate the production of antibodies. Finally, conjugate vaccines protect against bacteria that are encapsulated in  polysaccharides (complex sugars), which disguise the bacteria, making it hard for the immune system to recognize them. Conjugate vaccines overcome this by attaching the sugar to a protein the does stimulate the immune systeme, thus triggering the immune system to react to the sugar in the future even if it is not accompanied by the protein.<ref>https://www.cdc.gov/vaccines/hcp/conversations/downloads/vacsafe-understand-color-office.pdf</ref>

Since the adoption of mass vaccination programs, many diseases have been curbed. [[Smallpox]], a deadly disease responsible for the deaths of millions, has been entirely eliminated through vaccination, excepting some strains maintained in labs for research or weapons purposes. Responsible for an estimated 300 to 500 million deaths worldwide in the 20th century, vaccination programs of the 19th and 20th century were effective at curbing the disease, and in 1979 the World Health Organization declared smallpox to be eradicated.{{cn}}

Since the adoption of mass vaccination programs, many diseases have been curbed. [[Smallpox]], a deadly disease responsible for the deaths of millions, has been entirely eliminated through vaccination, excepting some strains maintained in labs for research or weapons purposes. Responsible for an estimated 300 to 500 million deaths worldwide in the 20th century, vaccination programs of the 19th and 20th century were effective at curbing the disease, and in 1979 the World Health Organization declared smallpox to be eradicated.{{cn}}