Changes

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 immunocompromised 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 system, 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>

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 immunocompromised 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 system, 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>

==Influenza Vaccine==

===Influenza Vaccine===

The flu vaccine is an example of modern vaccination. Due to the change in [[allele]] frequency over time in the population of the influenza virus, new influenza vaccines are created each year.  In some years the vaccines are less effective than in other years. According to the CDC,"Influenza viruses are always changing. Therefore, influenza vaccines are updated every year, and annual vaccination is recommended".<ref> "Inactivated Influenza Vaccine, What you need to know," a publication of the Center for Disease Control, 2006. Available online at: https://www.cdc.gov/nip/publications/VIS/vis-flu.pdf</ref>

The flu vaccine is an example of modern vaccination. Due to the change in [[allele]] frequency over time in the population of the influenza virus, new influenza vaccines are created each year.  In some years the vaccines are less effective than in other years. According to the CDC,"Influenza viruses are always changing. Therefore, influenza vaccines are updated every year, and annual vaccination is recommended".<ref> "Inactivated Influenza Vaccine, What you need to know," a publication of the Center for Disease Control, 2006. Available online at: https://www.cdc.gov/nip/publications/VIS/vis-flu.pdf</ref>

Since the production of the vaccine must begin many months before the influenza season starts models of the population genetics of the virus must be produced.<ref>http://www.nature.com/nrd/journal/v5/n3/full/nrd1988.html Influenza vaccines</ref> The success of vaccinations programs is dependent on the accuracy of these predictions.<ref>http://www.nature.com/news/2003/030324/full/030324-5.html Flu changes modeled</ref> The National Institute of Health recently assigned $26 million to establish a research center to better develop molecular models of influenza.<ref>http://www.spiritindia.com/health-care-news-articles-8024.html $26 million NIH contract to establish new flu/bird flu Center of Excellence</ref>

Since the production of the vaccine must begin many months before the influenza season starts models of the population genetics of the virus must be produced.<ref>http://www.nature.com/nrd/journal/v5/n3/full/nrd1988.html Influenza vaccines</ref> The success of vaccinations programs is dependent on the accuracy of these predictions.<ref>http://www.nature.com/news/2003/030324/full/030324-5.html Flu changes modeled</ref> The National Institute of Health recently assigned $26 million to establish a research center to better develop molecular models of influenza.<ref>http://www.spiritindia.com/health-care-news-articles-8024.html $26 million NIH contract to establish new flu/bird flu Center of Excellence</ref>

== See also ==

== See also ==

*[[Vaccine Injury Compensation Program]]

*[[Vaccine Injury Compensation Program]]

*[[Vaccine Adverse Event Reporting System]]

*[[Vaccine Adverse Event Reporting System]]

*[[Acellular vaccine]]

*[[Acellular vaccine]]

*[[Vaccine FAQ]]

*[[Vaccine FAQ]]

 

==External links==

==External links==