Changes

*Inactivated polio vaccine (IPV).  This is an injected vaccine that is now widely used in the US.

*Inactivated polio vaccine (IPV).  This is an injected vaccine that is now widely used in the US.

===Small pox===

===Small pox===

[[Edward Jenner]] ( 1749 – 1823) discovered that milkmaids developed an immunity to [[smallpox]], because they had earlier contracted cowpox. Cowpox is an uncommon, mild disease of animals, first observed in cows, closely related to the virus that causes smallpox. This led to the invention of a smallpox vaccine, which Jenner first tested in May 14, 1796, by inoculating eight-year-old James Phipps,  the son of his gardener.<ref>Stefan Riedel, MD (January 2005). "Edward Jenner and the history of smallpox and vaccination". Proceedings (Baylor University. Medical Center). Baylor University Medical Center. 18 (1): 21–25.</ref>

[[Edward Jenner]] ( 1749 – 1823) discovered that milkmaids developed an immunity to [[smallpox]], because they had earlier contracted cowpox. Cowpox is an uncommon, mild disease of animals, first observed in cows, closely related to the virus that causes smallpox. This led to the invention of a smallpox vaccine, which Jenner first tested on May 14, 1796, by inoculating eight-year-old James Phipps,  the son of his gardener.<ref>Stefan Riedel, MD (January 2005). "Edward Jenner and the history of smallpox and vaccination". Proceedings (Baylor University. Medical Center). Baylor University Medical Center. 18 (1): 21–25.</ref>

===Influenza===

===Influenza===

The [[flu]] vaccine is an example of modern vaccination. Due to [[genetic]] changes in 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 [[genetic]] changes in 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 vaccination 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 vaccination 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>