Changes

==Adverse Events==

==Adverse Events==

Only live attenuated vaccines can still cause infection. All vaccines can cause illness, but this is commonly a hypersensitivity reaction (similar to an allergic response), not due to the disease itself. Very rarely a serious disease known as [[eczema vaccinatum]] can emerge. Vaccines that use pieces of pathogens often use a [[carrier virus]] in the injection. Those with very weak immune systems that are exposed to such a vaccine can become infected with the carrier virus and develop [[eczema]]. A recent case of this was reported in the United States after a military man was vaccinated with small pox and his two year old son became ill.<ref>http://www.associatedcontent.com/article/183349/soldier_infects_toddler_son_with_lifethreatening.html AP article on eczema vaccinatum</ref>

Only live attenuated vaccines can still cause infection. All vaccines can cause illness, but this is commonly a hypersensitivity reaction (similar to an allergic response), not due to the disease itself. Very rarely a serious disease known as [[eczema vaccinatum]] can emerge. Vaccines that use pieces of pathogens often use a [[carrier virus]] in the injection. Those with very weak immune systems that are exposed to such a vaccine can become infected with the carrier virus and develop [[eczema]]. A recent case of this was reported in the United States after a military man was vaccinated with smallpox and his two-year-old son became ill.<ref>http://www.associatedcontent.com/article/183349/soldier_infects_toddler_son_with_lifethreatening.html AP article on eczema vaccinatum</ref>

A number of vaccination reactions are deemed serious enough to contraindicate further vaccinations of the same type. These include extensive swelling and redness at the injection site, prolonged fever, [[bronchospasm]] and laryngeal [[edema]](narrowing of the airways causing difficulty in breathing), and collapse/seizures with or without unconsciousness and/or encephalitis.<ref>[http://www.gpnotebook.co.uk/simplepage.cfm?ID=2067071044 General Practice Notebook - vaccine reactions]</ref>

A number of vaccination reactions are deemed serious enough to contraindicate further vaccinations of the same type. These include extensive swelling and redness at the injection site, prolonged fever, [[bronchospasm]] and laryngeal [[edema]](narrowing of the airways causing difficulty in breathing), and collapse/seizures with or without unconsciousness and/or encephalitis.<ref>[http://www.gpnotebook.co.uk/simplepage.cfm?ID=2067071044 General Practice Notebook - vaccine reactions]</ref>

Influenza viruses are always changing. Therefore, influenza vaccines are updated every year, and an annual vaccination is recommended.

Influenza viruses are always changing. Therefore, influenza vaccines are updated every year, and an annual vaccination is recommended.

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Since 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 dollars 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 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>

==Herd immunity and mandatory vaccination==

==Herd immunity and mandatory vaccination==

A concept in vaccine planning is "[[herd immunity]]". When a certain percentage of a population is vaccinated, those within the population who are not vaccinated are protected from the disease. If 90 percent of a population is immune, then the chances that a carrier of the disease will come into contact with a non-immune member of the population (or "herd") is low.<ref>http://www.mathepi.com/maindir/herd.html The mathematics of herd immunity</ref> Herd immunity is the goal of most vaccination programs as it is the point where a disease can start to be eliminated altogether from a population.  

A concept in vaccine planning is "[[herd immunity]]". When a certain percentage of a population is vaccinated, those within the population who are not vaccinated are protected from the disease. If 90 percent of a population is immune, then the chances that a carrier of the disease will come into contact with a non-immune member of the population (or "herd") is low.<ref>http://www.mathepi.com/maindir/herd.html The mathematics of herd immunity</ref> Herd immunity is the goal of most vaccination programs as it is the point where a disease can start to be eliminated altogether from a population.  

For example, in 1962 Japan instituted mandatory vaccination against influenza in school children. This continued until 1987 when the program was changed to optional; it was abandoned in 1994. Approximately 85 percent of children were estimated to have been vaccinated.<ref>{{hnb|Glezen|2004}}</ref> Several studies examined the mortality rates due to influenza during this period of time and revealed that the death rates due to influenza in all population groups was drastically decreased, including older adult populations. Since there was no increased rate of vaccination in these populations, the decreased mortality was caused by herd immunity effects of vaccinating so many children.<ref>http://www.newsrx.com/newsletters/Vaccine-Weekly/2001-04-11/200104113335VW.html Mandatory Vaccination of Japanese Schoolchildren Demonstrates "Herd Immunity"</ref> Many researchers have written that this and other evidence argues strongly for mandatory vaccination programs world wide as a means of controlling many diseases and preventing a [[pandemic]].<ref>http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1360502 Herd Immunity</ref>

For example, in 1962 Japan instituted mandatory vaccination against influenza in school children. This continued until 1987 when the program was changed to optional; it was abandoned in 1994. Approximately 85 percent of children were estimated to have been vaccinated.<ref>{{hnb|Glezen|2004}}</ref> Several studies examined the mortality rates due to influenza during this period of time and revealed that the death rates due to influenza in all population groups was drastically decreased, including older adult populations. Since there was no increased rate of vaccination in these populations, the decreased mortality was caused by herd immunity effects of vaccinating so many children.<ref>http://www.newsrx.com/newsletters/Vaccine-Weekly/2001-04-11/200104113335VW.html Mandatory Vaccination of Japanese Schoolchildren Demonstrates "Herd Immunity"</ref> Many researchers have written that this and other evidence argues strongly for mandatory vaccination programs worldwide as a means of controlling many diseases and preventing a [[pandemic]].<ref>http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1360502 Herd Immunity</ref>

The USA has mandatory vaccination according to an official CDC schedule. Enforcement is left to the states. Most states have medical and religious exemptions. Some states make it very easy to opt out of vaccines, while other states strictly enforce compliance for school attendance. The difference in vaccination rates between these states is actually very slight, and usually not nearly enough to affect herd immunity.  

The USA has mandatory vaccination according to an official CDC schedule. Enforcement is left to the states. Most states have medical and religious exemptions. Some states make it very easy to opt out of vaccines, while other states strictly enforce compliance for school attendance. The difference in vaccination rates between these states is actually very slight, and usually not nearly enough to affect herd immunity.  

== Adverse Reactions ==

== Adverse Reactions ==

{{See also|Vaccine Injury Compensation Program|Vaccine Adverse Event Reporting System}}

{{See also|Vaccine Injury Compensation Program|Vaccine Adverse Event Reporting System}}

Vaccines are not completely harmless, and many have a significant morbidity and mortality associated with them. Postvaccinial encephalitis is a known hazard of [[smallpox]] vaccine, for example. A recently-introduced vaccine against [[human papilloma virus]], the [[causative agent]] of [[cancer]] of the [[uterus|uterine]] [[cervix]], has now been linked to a number of sudden deaths reported within days of its administration.<ref name=GardasilMM>Cockcroft, Lucy, "[http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2007/10/29/njab129.xml Cervical cancer drug Gardasil linked to deaths]," ''[[London]] Daily Telegraph'', October 29, 2007. Retrieved November 10, 2007.</ref>

Vaccines are not completely harmless, and many have a significant morbidity and mortality associated with them. Postvaccinial encephalitis is a known hazard of [[smallpox]] vaccine, for example. A recently introduced vaccine against [[human papilloma virus]], the [[causative agent]] of [[cancer]] of the [[uterus|uterine]] [[cervix]], has now been linked to a number of sudden deaths reported within days of its administration.<ref name=GardasilMM>Cockcroft, Lucy, "[http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2007/10/29/njab129.xml Cervical cancer drug Gardasil linked to deaths]," ''[[London]] Daily Telegraph'', October 29, 2007. Retrieved November 10, 2007.</ref>

Bulging or swollen [[fontanelle]]s have been linked with many vaccines commonly given to infants, such as the [[diptheria]]-[[tetanus]] (DPT) vaccine. Many families, out of concern for their child's health, have sought legal justice for the potential health damage.<ref>http://legaljustice4john.com/fontanellebulging.htm</ref>

Bulging or swollen [[fontanelle]]s have been linked with many vaccines commonly given to infants, such as the [[diptheria]]-[[tetanus]] (DPT) vaccine. Many families, out of concern for their child's health, have sought legal justice for the potential health damage.<ref>http://legaljustice4john.com/fontanellebulging.htm</ref>

Many people assume that official vaccine recommendations are based on recommendations of independent panels of experts after reviewing risk-benefit and cost-benefit analyses. They are not. The government panels are dominated by vaccine industry representatives and they have no consumer representatives. The meetings are not open to the public. They do not usually do much analysis, and tend to recommend whatever vaccines are available{{fact}}

Many people assume that official vaccine recommendations are based on recommendations of independent panels of experts after reviewing risk-benefit and cost-benefit analyses. They are not. The government panels are dominated by vaccine industry representatives and they have no consumer representatives. The meetings are not open to the public. They do not usually do much analysis, and tend to recommend whatever vaccines are available{{fact}}

Misinformed rumors about vaccines do not happen only in the developed world. The world wide polio eradication came to a halt in 2003 when Muslim Imams in Nigeria began spreading rumors that the vaccines would give boys HIV and sterilize girls. The vaccine was banned for over a year in the country. The ban has since been lifted, but the vaccination rate remains low.

Misinformed rumors about vaccines do not happen only in the developed world. The worldwide polio eradication came to a halt in 2003 when Muslim Imams in Nigeria began spreading rumors that the vaccines would give boys HIV and sterilize girls. The vaccine was banned for over a year in the country. The ban has since been lifted, but the vaccination rate remains low.

==References==

==References==