Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your Vaccine shopping experience:
1. Compare - without doubt the biggest advantage that the Vaccine offers shoppers today is the ability to compare thousands of Vaccine at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.
2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about
3. Testimonials - don't know anybody that has bought a Vaccine? Wrong! If the Vaccine is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.
4. Questions - Got a question about Vaccine then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....
5. Reputation - Never heard of the company selling Vaccine? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about Vaccine and build up a picture of their reputation for sales, returns, customer service, delivery etc.
6. Returns - still worried that even after all of the above your Vaccine wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.
7. Feedback - happy with your Vaccine then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.
8. Security - check for the yellow padlock on the Vaccine site before you buy, and the s after http:/ /i.e. https:// = a secure site
9. Contact - got a question about Vaccine, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.
10. Payment - ready to pay for your Vaccine, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.
A
vaccine is an antigenic preparation used to establish
immunity (medical) to a disease. The term derives from
Edward Jenner's use of cowpox ("vacca" means cow in Latin), which, when administered to humans, provided them protection against
smallpox, the work which
Louis Pasteur and others carried on. Vaccines are based on the concept of variolation originating in China, in which a person is deliberately infected with a weak form of smallpox. Jenner realized that milkmaids who had contact with cowpox did not get smallpox. The process of distributing and administrating vaccines is referred to as
vaccination. Since vaccination was much safer, smallpox inoculation fell into disuse and was eventually banned in England in 1840.
Vaccines can be
prophylaxis (e.g. to prevent or ameliorate the effects of a future
infection by any natural or "wild" pathogen), or Drug therapy (e.g. vaccines against cancer are also being investigated; see cancer vaccine).
Types of vaccines
vaccine development by
reverse genetics techniques.Vaccines may be dead or inactivated organisms or purified products derived from them.
There are four types of traditional vaccines:
- Vaccines containing killed microorganisms - these are previously virulent micro-organisms that have been killed with chemicals or heat. Examples are vaccines against Flu vaccine, cholera, bubonic plague, and hepatitis A.
- Vaccines containing live, attenuated microorganisms - these are live micro-organisms that have been cultivated under conditions that disable their virulent properties. They typically provoke more durable immunological responses and are the preferred type for healthy adults. Examples include yellow fever, measles, rubella, and mumps.
- Toxoids - these are inactivated toxic compounds from micro-organisms in cases where these (rather than the micro-organism itself) cause illness. Examples of toxoid-based vaccines include tetanus and diphtheria.
- Subunit - rather than introducing an inactivated or attenuated micro-organism to an immune system, a fragment of it can create an immune response. Characteristic examples include the subunit vaccine against HBV that is composed of only the surface proteins of the virus (produced in yeast) and the virus like particle (VLP) vaccine against Human Papillomavirus (HPV) that is composed of the viral major capsid protein.
The live tuberculosis vaccine is not the contagious strain, but a related strain called "Bacillus Calmette-Guérin"; it is used in the United States very infrequently.
A number of innovative vaccines are also in development and in use:
- Conjugate vaccine - certain bacteria have polysaccharide outer coats that are poorly immunogenic. By linking these outer coats to proteins (e.g. toxins), the immune system can be led to recognize the polysaccharide as if it were a protein antigen. This approach is used in the Haemophilus influenzae type B vaccine.
- Recombinant DNA Vector - by combining the physiology of one micro-organism and the DNA of the other, immunity can be created against diseases that have complex infection processes
- DNA vaccination - in recent years a new type of vaccine, created from an infectious agent's DNA called DNA vaccination, has been developed. It works by insertion (and Gene expression, triggering immune system recognition) into human or animal cells, of viral or bacterial DNA. Some cells of the immune system that recognize the proteins expressed will mount an attack against these proteins and cells expressing them. Because these cells live for a very long time, if the pathogen that normally expresses these proteins is encountered at a later time, they will be attacked instantly by the immune system. One advantage of DNA vaccines is that they are very easy to produce and store. As of 2006, DNA vaccination is still experimental, but shows some promising results.
Note that while most vaccines are created using inactivated or attenuated compounds from micro-organisms,
synthetic vaccines are composed mainly or wholly of synthetic peptides, carbohydrates or antigens. Some viral vaccines have been developed by use of cell lines derived from aborted fetuses ( http://www.lifecanada.org/html/science/Vaccines/ABriefHistoryofHumanDiploidCellStrains.pdf )
Developing immunity
The immune system recognizes vaccine agents as foreign, destroys them, and 'remembers' them. When the
virulent version of an agent comes along, the
immune system is thus prepared to respond, by (1) neutralizing the target agent before it can enter cells, and (2) by recognizing and destroying infected cells before that agent can multiply to vast numbers.
Vaccines have contributed to the eradication of smallpox, one of the most contagious and deadly diseases known to man. Other diseases such as rubella, polio, measles, mumps, chickenpox, and
typhoid are nowhere near as common as they were just a hundred years ago. As long as the vast majority of people are vaccinated, it is much more difficult for an outbreak of disease to occur, let alone spread. This effect is called
herd immunity. Polio, which is transmitted only between humans, is targeted by an extensive
Polio eradication that has seen endemic polio restricted to only parts of four countries. The difficulty of reaching all children, however, has caused the eradication date to be missed twice by 2006.
Vaccination schedule
Main article: Vaccination schedule
See also: Vaccination policy
In order to provide best protection, children are recommended to receive vaccinations as soon as their immune systems are sufficiently developed to respond to particular vaccines, with additional 'booster' shots often required to achieve 'full immunity'. This has led to the development of complex vaccination schedules. In the United States, the Advisory Committee on Immunization Practices, which recommends schedule additions for the
Center for Disease Control, recommends routine vaccination of children against: hepatitis A,
hepatitis B, polio,
mumps, measles,
rubella, diphtheria, pertussis,
tetanus, Haemophilus influenzae, chicken pox, rotavirus, influenza,
meningococcal disease and
pneumonia. The large number of vaccines and boosters recommended (up to 24 injections by age two) has led to problems with achieving full compliance. In order to combat declining compliance rates, various notification systems have been instituted and a number of combination injections are now marketed (e.g.,
Prevnar and ProQuad vaccines), which provide protection against multiple diseases.
Besides recommendations for infant vaccination boosters, many specific vaccines are recommended for repeated injections throughout life -- most commonly for measles, tetanus, influenza, and pneumonia. Pregnant women are often screened for continued resistance to rubella. In 2006, a vaccine was introduced against shingles, a disease caused by the chicken pox virus, which usually affects the elderly. Vaccine recommendations for the elderly concentrate on pneumonia and influenza, which are more deadly to that group.
Vaccine controversies
Antivaccinationist, from a wide array of vaccine critics, has existed since the earliest vaccination campaigns: .
A number of vaccines, including those given to very young children, have contained thiomersal, a preservative that metabolizes into ethylmercury. It has been used in some
influenza, DTP (
diphtheria, tetanus and
pertussis) vaccine formulations. Since
1997, use of thimerosal has been gradually diminishing in western industrialized countries after recommendations by medical authorities, but trace amounts of thimerosal remain in many vaccines and in some vaccines, thimerosal has not yet been phased out despite recommendations. Some states in the USA have enacted laws banning the use of thimerosal in childhood vaccines.
In the late 1990s, controversy over vaccines escalated in both the US and the United Kingdom when a study, published in the respected journal
Lancet, by
Andrew Wakefield suggested a possible link between bowel disorders, autism and the MMR vaccine, and urged further research. His report garnered significant media attention, leading to a drop in the uptake of the MMR vaccine in the United Kingdom and some other countries. In response to the controversies, a number of studies with larger sample sizes were conducted, and failed to confirm the findings. . In 2004, 10 of the 13 authors of the original Wakefield study retracted the paper's "interpretation", or conclusion, section, which had claimed:
"Interpretation. We identified associated gastrointestinal disease and developmental regression in a group of previously normal children, which was generally associated in time with possible environmental triggers."The retraction of this claim stated that the data were insufficient to establish a causal link between MMR vaccine and autism. Wakefield was later found to have received £435,000 in fees from trial lawyers attempting to show the vaccine was dangerous . Also in 2004, the United States' Institute of Medicine reported that evidence "favors rejection" of any link between vaccines containing thimerosal, or MMR, and the development of autism .
In 2004 and
2005, England and Wales experienced an increase in the incidence of mumps infections among adolescents and young adults. The age group affected were too old to have received the routine MMR immunisations around the time the paper by Wakefield et al was published, and too young to have contracted natural mumps as a child, and thus to achieve a
herd immunity effect. With the decline in mumps that followed the introduction of the MMR vaccine, these individuals had not been exposed to the disease, but still had no immunity, either natural or vaccine induced. Therefore, as immunization rates declined following the controversy and the disease re-emerged, they were susceptible to infection. . This and similar examples indicate the importance of:
careful modelling to anticipate the impact that an immunisation campaign will have on the epidemiology of the disease in the medium to long term
ongoing surveillance for the relevant disease following introduction of a new vaccine and
maintaining high immunisation rates, even when a disease has become rare.
There is opposition to any type of vaccination from some sectors of the community, particularly those who favor 'alternative' health care. Some skeptics claim that mass immunization is a
eugenics program. Naturopaths and other alternative health care practitioners sometimes offer their own, alternative treatments to conventional vaccination.
In Australia, a massive increase in vaccination rates was observed when the federal government made certain benefits (such as the universal 'Family Allowance' welfare payments for parents of children) dependent on vaccination. As well, children were not allowed into school unless they were either vaccinated or their parents completed a statutory declaration refusing to immunize them, after discussion with a doctor, and other bureaucracy. (Similar school-entry vaccination regulations have been in place in some parts of Canada for several years.) It became easier and cheaper to vaccinate one's children than not to. When faced with the annoyance, many more casual objectors simply gave in.
Another vaccination controversy concerns smallpox. Since it has been eradicated, some suggest that the stores of smallpox virus should be destroyed. In an article on Newswise both sides debate the issue: "The destruction of remaining smallpox virus stocks is an overdue step forward for public health and security that will dramatically reduce the possibility that this scourge will kill again, either by accident or design, argues Edward Hammond of The Sunshine Project, an organisation seeking international consensus against biological weapons."
"But John Agwunobi of the US Department of Health and Human Services believes that clandestine stocks almost certainly exist and that destroying the virus would be “irreversible and short sighted.”
==Efficacy of vaccines==Vaccines do not guarantee complete protection from a disease. Sometimes this is because the host's immune system simply doesn't respond adequately or at all. This may be due to a lowered immunity in general (diabetes, steroid use, HIV infection) or because the host's immune system does not have a B-cell capable of generating antibodies to that antigen.
Even if the host develops antibodies, the human immune system is not perfect and in any case the immune system might still not be able to defeat the infection.
Immunologic adjuvants are typically used to boost immune response. Adjuvants are sometimes called the
dirty little secret of vaccines in the scientific community, as not much is known about how adjuvants work. Most often aluminium adjuvants are used, but adjuvants like squalene are also used in some vaccines and more vaccines with squalene and phosphate adjuvants are being tested.The
vaccine efficacy or performance of the vaccine is dependent on a number of factors:
- the disease itself (for some diseases vaccination performs better than for other diseases)
- the strain of vaccine (some vaccinations are for different strains of the disease)
- whether one kept to the timetable for the vaccinations (see Vaccination schedule)
- some individuals are 'non-responders' to certain vaccines, meaning that they do not generate antibodies even after being vaccinated correctly
- other factors such as ethnicity or genetic predisposition
When a vaccinated individual does develop the disease vaccinated against, the disease is likely to be milder than without vaccination.
Economics of vaccine development
One challenge in vaccine development is economic: many of the diseases most demanding a vaccine, including HIV,
malaria and
tuberculosis, exist principally in poor countries. Although some contend pharmaceutical firms and biotech companies have little incentive to develop vaccines for these diseases, because there is little revenue potential, the number of vaccines actually administered has risen dramatically in recent decades. This increase, particularly in the number of different vaccines administered to children before entry into schools may be due to government mandates, rather than economic incentive. Most vaccine development to date has relied on 'push' funding by government and non-profit organizations, of government agencies, universities and non-profit organizations.
Many researchers and policymakers are calling for a different approach, using 'pull' mechanisms to motivate industry. Mechanisms such asprizes, tax credits, or advance market commitments could ensure a financial return to firms that successfully developed a HIV vaccine. If the policy were well-designed, it might also ensure people have access to a vaccine if and when it is developed.
Statistics from the government agencies of the U.S., the British Commonwealth and the U.K. show that between the 1800s and the time various vaccines were introduced, the incidences of the diseases for which vaccines were provided were reduced by 70%-90%. For some, this prompts the question as to whether the reduction in the morbidity and mortality due to these diseases is owed to improved sewage systems, food refrigeration, improved home and work environments, and the introduction of antibiotics, all of which occurred during the same period.
Preservatives
In order to extend shelf life and reduce production and storage costs,
thimerosal, a preservative containing about 49% of a form of Mercury (element) called ethylmercury, was used routinely until recent years. Thimerosal has been phased out in the U.S. in all but a few flu vaccines (it has been phased out earlier in other countries, e.g. Denmark in 1992), but may be used in stages of manufacture. Parents wishing to avoid this preservative, most common in multi-dose containers of influenza vaccine, may specifically ask for thimerosal-free alternatives that contain only trace amounts.
A study published in the September 2007 New England Journal of Medicine reported no causal association between early exposure to mercury from thimerosal-containing vaccines and neurological problems by the age of 7 to 10 years old.
Vaccines for nonhumans
See also
References
- AAPPublications.org - 'Thimerosal and the Occurrence of Autism: Negative Ecological Evidence From Danish Population-Based Data' Pediatrics, Vol 112, No 3, September 2003 (Denmark study on autism rates)
- BMJJournals.com - 'Comparative efficacy of three mumps vaccines', Matthias Schlegel, Joseph J. Osterwalder, Renato L. Galeazzi, Pietro J. Vernazza, British Medical Journal' Vol 319, No 352, August 7, 1999
- UNT.edu - Congressional Research Service (CRS) Reports regarding vaccines University of North Texas
- Vaccine Information.org - 'Vaccine Information for the Public and Health Professionals: Information about vaccine preventable diseases', Immunization Action Coalition
- SI.edu - 'History of Vaccines', Smithsonian Institute
- cdc.gov - Mercury and Vaccines (Thimerosal) from the CDC
- dissidentvoice.org - 'Bush Puppets Push for New Law to Protect Drug Companies', Dissident Voice
- Expert Review of Vaccines. Peer-reviewed journal published by Future Science Group
- Vaccination of Humans Encyclopedia of Life Sciences: Wiley Interscience. January 2006.
- Vaccination Encyclopedia of Life Sciences: Wiley Interscience. September 2005.
- Leiva R. A brief history of human diploid cell strains. Natl Cathol Bioeth Q. 2006 Autumn;6(3):443-51 http://www.lifecanada.org/html/science/Vaccines/ABriefHistoryofHumanDiploidCellStrains.pdf
External links
General
- Vaccines: Types and development - University of Arizona
- Vaccines Licensed for Immunization and Distribution in the US
- Website for Arthur Allen's 2007 book, "Vaccine, the Controversial History of Medicine's Greatest Lifesaver" (WW Norton)
- Vaccine news, information, and commentary from the University of Pennsylvania Center for Bioethics
Vaccine proponent views
- CGDev.org -'Vaccines for Development' (updated regularly), Center for Global Development
- ClearlyExplained.com - 'Vaccines', Richard Conan-Davies, BSc Dip Ed (October 22, 2001)
- NIH.gov - 'Immunization' ('conventional' opinion on vaccines), National Institute of Health
- TownHall.com - 'Don't believe the childhood vaccine fearmongers', Michael Fumento (June 30, 2005)
Vaccine safety critical views
-
- MacroBiotic.net - 'A Short History of Vaccines'
- IOM.edu (pdf) - 'Before the Institute of Medicine' (statement on link between thimerosol and autism), US Congressman Dave Weldon, MD, (February 9, 2004)
- Liberty-Page.com - 'Bad Medicine: Or...How government interference in the vaccine market causes shortages, intellectual stagnation and death.'
- NoVaccine.com - 'The World Association for Vaccine Education' (WAVE), Dan Schultz, DC
- Immunisation Awareness Society (IAS) New Zealand
- Think Twice Global vaccine institute
- Vaccination Liberation
A
vaccine is an antigenic preparation used to establish immunity (medical) to a disease. The term derives from Edward Jenner's use of cowpox ("vacca" means cow in
Latin), which, when administered to humans, provided them protection against
smallpox, the work which Louis Pasteur and others carried on. Vaccines are based on the concept of variolation originating in China, in which a person is deliberately infected with a weak form of smallpox. Jenner realized that milkmaids who had contact with cowpox did not get smallpox. The process of distributing and administrating vaccines is referred to as vaccination. Since vaccination was much safer, smallpox inoculation fell into disuse and was eventually banned in England in 1840.
Vaccines can be prophylaxis (e.g. to prevent or ameliorate the effects of a future infection by any natural or "wild" pathogen), or Drug therapy (e.g. vaccines against cancer are also being investigated; see
cancer vaccine).
Types of vaccines
vaccine development by reverse genetics techniques.Vaccines may be dead or inactivated organisms or purified products derived from them.
There are four types of traditional vaccines:
- Vaccines containing killed microorganisms - these are previously virulent micro-organisms that have been killed with chemicals or heat. Examples are vaccines against Flu vaccine, cholera, bubonic plague, and hepatitis A.
- Vaccines containing live, attenuated microorganisms - these are live micro-organisms that have been cultivated under conditions that disable their virulent properties. They typically provoke more durable immunological responses and are the preferred type for healthy adults. Examples include yellow fever, measles, rubella, and mumps.
- Toxoids - these are inactivated toxic compounds from micro-organisms in cases where these (rather than the micro-organism itself) cause illness. Examples of toxoid-based vaccines include tetanus and diphtheria.
- Subunit - rather than introducing an inactivated or attenuated micro-organism to an immune system, a fragment of it can create an immune response. Characteristic examples include the subunit vaccine against HBV that is composed of only the surface proteins of the virus (produced in yeast) and the virus like particle (VLP) vaccine against Human Papillomavirus (HPV) that is composed of the viral major capsid protein.
The live tuberculosis vaccine is not the
contagious strain, but a related strain called "
Bacillus Calmette-Guérin"; it is used in the United States very infrequently.
A number of innovative vaccines are also in development and in use:
- Conjugate vaccine - certain bacteria have polysaccharide outer coats that are poorly immunogenic. By linking these outer coats to proteins (e.g. toxins), the immune system can be led to recognize the polysaccharide as if it were a protein antigen. This approach is used in the Haemophilus influenzae type B vaccine.
- Recombinant DNA Vector - by combining the physiology of one micro-organism and the DNA of the other, immunity can be created against diseases that have complex infection processes
- DNA vaccination - in recent years a new type of vaccine, created from an infectious agent's DNA called DNA vaccination, has been developed. It works by insertion (and Gene expression, triggering immune system recognition) into human or animal cells, of viral or bacterial DNA. Some cells of the immune system that recognize the proteins expressed will mount an attack against these proteins and cells expressing them. Because these cells live for a very long time, if the pathogen that normally expresses these proteins is encountered at a later time, they will be attacked instantly by the immune system. One advantage of DNA vaccines is that they are very easy to produce and store. As of 2006, DNA vaccination is still experimental, but shows some promising results.
Note that while most vaccines are created using inactivated or attenuated compounds from micro-organisms,
synthetic vaccines are composed mainly or wholly of synthetic peptides, carbohydrates or antigens. Some viral vaccines have been developed by use of cell lines derived from aborted fetuses ( http://www.lifecanada.org/html/science/Vaccines/ABriefHistoryofHumanDiploidCellStrains.pdf )
Developing immunity
The immune system recognizes vaccine agents as foreign, destroys them, and 'remembers' them. When the virulent version of an agent comes along, the
immune system is thus prepared to respond, by (1) neutralizing the target agent before it can enter cells, and (2) by recognizing and destroying infected cells before that agent can multiply to vast numbers.
Vaccines have contributed to the eradication of
smallpox, one of the most contagious and deadly diseases known to man. Other diseases such as rubella,
polio, measles, mumps,
chickenpox, and typhoid are nowhere near as common as they were just a hundred years ago. As long as the vast majority of people are vaccinated, it is much more difficult for an outbreak of disease to occur, let alone spread. This effect is called
herd immunity. Polio, which is transmitted only between humans, is targeted by an extensive Polio eradication that has seen endemic polio restricted to only parts of four countries. The difficulty of reaching all children, however, has caused the eradication date to be missed twice by 2006.
Vaccination schedule
Main article: Vaccination schedule
See also: Vaccination policy
In order to provide best protection, children are recommended to receive vaccinations as soon as their immune systems are sufficiently developed to respond to particular vaccines, with additional 'booster' shots often required to achieve 'full immunity'. This has led to the development of complex vaccination schedules. In the United States, the Advisory Committee on Immunization Practices, which recommends schedule additions for the
Center for Disease Control, recommends routine vaccination of children against: hepatitis A,
hepatitis B,
polio, mumps, measles, rubella, diphtheria,
pertussis, tetanus,
Haemophilus influenzae, chicken pox, rotavirus,
influenza,
meningococcal disease and pneumonia. The large number of vaccines and boosters recommended (up to 24 injections by age two) has led to problems with achieving full compliance. In order to combat declining compliance rates, various notification systems have been instituted and a number of combination injections are now marketed (e.g., Prevnar and
ProQuad vaccines), which provide protection against multiple diseases.
Besides recommendations for infant vaccination boosters, many specific vaccines are recommended for repeated injections throughout life -- most commonly for measles, tetanus, influenza, and pneumonia. Pregnant women are often screened for continued resistance to rubella. In 2006, a vaccine was introduced against shingles, a disease caused by the chicken pox virus, which usually affects the elderly. Vaccine recommendations for the elderly concentrate on pneumonia and influenza, which are more deadly to that group.
Vaccine controversies
Antivaccinationist, from a wide array of vaccine critics, has existed since the earliest vaccination campaigns: .
A number of vaccines, including those given to very young children, have contained
thiomersal, a preservative that metabolizes into ethylmercury. It has been used in some
influenza, DTP (diphtheria,
tetanus and pertussis) vaccine formulations. Since 1997, use of thimerosal has been gradually diminishing in western industrialized countries after recommendations by medical authorities, but trace amounts of thimerosal remain in many vaccines and in some vaccines, thimerosal has not yet been phased out despite recommendations. Some states in the USA have enacted laws banning the use of thimerosal in childhood vaccines.
In the late 1990s, controversy over vaccines escalated in both the US and the
United Kingdom when a study, published in the respected journal
Lancet, by
Andrew Wakefield suggested a possible link between bowel disorders, autism and the MMR vaccine, and urged further research. His report garnered significant media attention, leading to a drop in the uptake of the MMR vaccine in the United Kingdom and some other countries. In response to the controversies, a number of studies with larger sample sizes were conducted, and failed to confirm the findings. . In 2004, 10 of the 13 authors of the original Wakefield study retracted the paper's "interpretation", or conclusion, section, which had claimed:
"Interpretation. We identified associated gastrointestinal disease and developmental regression in a group of previously normal children, which was generally associated in time with possible environmental triggers."The retraction of this claim stated that the data were insufficient to establish a causal link between MMR vaccine and autism. Wakefield was later found to have received £435,000 in fees from trial lawyers attempting to show the vaccine was dangerous . Also in 2004, the United States' Institute of Medicine reported that evidence "favors rejection" of any link between vaccines containing thimerosal, or MMR, and the development of autism .
In
2004 and 2005, England and Wales experienced an increase in the incidence of mumps infections among adolescents and young adults. The age group affected were too old to have received the routine MMR immunisations around the time the paper by Wakefield et al was published, and too young to have contracted natural mumps as a child, and thus to achieve a herd immunity effect. With the decline in mumps that followed the introduction of the MMR vaccine, these individuals had not been exposed to the disease, but still had no immunity, either natural or vaccine induced. Therefore, as immunization rates declined following the controversy and the disease re-emerged, they were susceptible to infection. . This and similar examples indicate the importance of:
careful modelling to anticipate the impact that an immunisation campaign will have on the epidemiology of the disease in the medium to long term
ongoing surveillance for the relevant disease following introduction of a new vaccine and
maintaining high immunisation rates, even when a disease has become rare.
There is opposition to any type of vaccination from some sectors of the community, particularly those who favor 'alternative' health care. Some skeptics claim that mass immunization is a eugenics program. Naturopaths and other alternative health care practitioners sometimes offer their own, alternative treatments to conventional vaccination.
In Australia, a massive increase in vaccination rates was observed when the federal government made certain benefits (such as the universal 'Family Allowance' welfare payments for parents of children) dependent on vaccination. As well, children were not allowed into school unless they were either vaccinated or their parents completed a statutory declaration refusing to immunize them, after discussion with a doctor, and other bureaucracy. (Similar school-entry vaccination regulations have been in place in some parts of Canada for several years.) It became easier and cheaper to vaccinate one's children than not to. When faced with the annoyance, many more casual objectors simply gave in.
Another vaccination controversy concerns smallpox. Since it has been eradicated, some suggest that the stores of smallpox virus should be destroyed. In an article on Newswise both sides debate the issue: "The destruction of remaining smallpox virus stocks is an overdue step forward for public health and security that will dramatically reduce the possibility that this scourge will kill again, either by accident or design, argues Edward Hammond of The Sunshine Project, an organisation seeking international consensus against biological weapons."
"But John Agwunobi of the US Department of Health and Human Services believes that clandestine stocks almost certainly exist and that destroying the virus would be “irreversible and short sighted.”
==Efficacy of vaccines==Vaccines do not guarantee complete protection from a disease. Sometimes this is because the host's immune system simply doesn't respond adequately or at all. This may be due to a lowered immunity in general (diabetes, steroid use, HIV infection) or because the host's immune system does not have a B-cell capable of generating antibodies to that antigen.
Even if the host develops antibodies, the human immune system is not perfect and in any case the immune system might still not be able to defeat the infection.
Immunologic adjuvants are typically used to boost immune response. Adjuvants are sometimes called the
dirty little secret of vaccines in the scientific community, as not much is known about how adjuvants work. Most often aluminium adjuvants are used, but adjuvants like
squalene are also used in some vaccines and more vaccines with squalene and phosphate adjuvants are being tested.The vaccine efficacy or performance of the vaccine is dependent on a number of factors:
- the disease itself (for some diseases vaccination performs better than for other diseases)
- the strain of vaccine (some vaccinations are for different strains of the disease)
- whether one kept to the timetable for the vaccinations (see Vaccination schedule)
- some individuals are 'non-responders' to certain vaccines, meaning that they do not generate antibodies even after being vaccinated correctly
- other factors such as ethnicity or genetic predisposition
When a vaccinated individual does develop the disease vaccinated against, the disease is likely to be milder than without vaccination.
Economics of vaccine development
One challenge in vaccine development is economic: many of the diseases most demanding a vaccine, including
HIV, malaria and tuberculosis, exist principally in poor countries. Although some contend pharmaceutical firms and biotech companies have little incentive to develop vaccines for these diseases, because there is little revenue potential, the number of vaccines actually administered has risen dramatically in recent decades. This increase, particularly in the number of different vaccines administered to children before entry into schools may be due to government mandates, rather than economic incentive. Most vaccine development to date has relied on 'push' funding by government and non-profit organizations, of government agencies, universities and non-profit organizations.
Many researchers and policymakers are calling for a different approach, using 'pull' mechanisms to motivate industry. Mechanisms such asprizes, tax credits, or
advance market commitments could ensure a financial return to firms that successfully developed a HIV vaccine. If the policy were well-designed, it might also ensure people have access to a vaccine if and when it is developed.
Statistics from the government agencies of the U.S., the British Commonwealth and the U.K. show that between the 1800s and the time various vaccines were introduced, the incidences of the diseases for which vaccines were provided were reduced by 70%-90%. For some, this prompts the question as to whether the reduction in the morbidity and mortality due to these diseases is owed to improved sewage systems, food refrigeration, improved home and work environments, and the introduction of antibiotics, all of which occurred during the same period.
Preservatives
In order to extend shelf life and reduce production and storage costs, thimerosal, a preservative containing about 49% of a form of
Mercury (element) called ethylmercury, was used routinely until recent years. Thimerosal has been phased out in the U.S. in all but a few flu vaccines (it has been phased out earlier in other countries, e.g. Denmark in 1992), but may be used in stages of manufacture. Parents wishing to avoid this preservative, most common in multi-dose containers of influenza vaccine, may specifically ask for thimerosal-free alternatives that contain only trace amounts.
A study published in the September 2007 New England Journal of Medicine reported no causal association between early exposure to mercury from thimerosal-containing vaccines and neurological problems by the age of 7 to 10 years old.
Vaccines for nonhumans
See also
References
- AAPPublications.org - 'Thimerosal and the Occurrence of Autism: Negative Ecological Evidence From Danish Population-Based Data' Pediatrics, Vol 112, No 3, September 2003 (Denmark study on autism rates)
- BMJJournals.com - 'Comparative efficacy of three mumps vaccines', Matthias Schlegel, Joseph J. Osterwalder, Renato L. Galeazzi, Pietro J. Vernazza, British Medical Journal' Vol 319, No 352, August 7, 1999
- UNT.edu - Congressional Research Service (CRS) Reports regarding vaccines University of North Texas
- Vaccine Information.org - 'Vaccine Information for the Public and Health Professionals: Information about vaccine preventable diseases', Immunization Action Coalition
- SI.edu - 'History of Vaccines', Smithsonian Institute
- cdc.gov - Mercury and Vaccines (Thimerosal) from the CDC
- dissidentvoice.org - 'Bush Puppets Push for New Law to Protect Drug Companies', Dissident Voice
- Expert Review of Vaccines. Peer-reviewed journal published by Future Science Group
- Vaccination of Humans Encyclopedia of Life Sciences: Wiley Interscience. January 2006.
- Vaccination Encyclopedia of Life Sciences: Wiley Interscience. September 2005.
- Leiva R. A brief history of human diploid cell strains. Natl Cathol Bioeth Q. 2006 Autumn;6(3):443-51 http://www.lifecanada.org/html/science/Vaccines/ABriefHistoryofHumanDiploidCellStrains.pdf
External links
General
- Vaccines: Types and development - University of Arizona
- Vaccines Licensed for Immunization and Distribution in the US
- Website for Arthur Allen's 2007 book, "Vaccine, the Controversial History of Medicine's Greatest Lifesaver" (WW Norton)
- Vaccine news, information, and commentary from the University of Pennsylvania Center for Bioethics
Vaccine proponent views
- CGDev.org -'Vaccines for Development' (updated regularly), Center for Global Development
- ClearlyExplained.com - 'Vaccines', Richard Conan-Davies, BSc Dip Ed (October 22, 2001)
- NIH.gov - 'Immunization' ('conventional' opinion on vaccines), National Institute of Health
- TownHall.com - 'Don't believe the childhood vaccine fearmongers', Michael Fumento (June 30, 2005)
Vaccine safety critical views
-
- MacroBiotic.net - 'A Short History of Vaccines'
- IOM.edu (pdf) - 'Before the Institute of Medicine' (statement on link between thimerosol and autism), US Congressman Dave Weldon, MD, (February 9, 2004)
- Liberty-Page.com - 'Bad Medicine: Or...How government interference in the vaccine market causes shortages, intellectual stagnation and death.'
- NoVaccine.com - 'The World Association for Vaccine Education' (WAVE), Dan Schultz, DC
- Immunisation Awareness Society (IAS) New Zealand
- Think Twice Global vaccine institute
- Vaccination Liberation
Vaccine Institute
The St George's Vaccine Institute is an independent, non-commercial, academic institution. The first phase opened in 1996 as a combined clinical, scientific and educational ...
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Vaccine - Elsevier
Editor: R.E. Spier See editorial board for all editors information Special Issue on HPV Vaccines and Screening in the Prevention of Cervical Cancer
Cancer Research UK | CancerHelp UK | Cervical cancer vaccine
I have heard about a vaccine to prevent a virus that causes cervical cancer. Can you tell me more about it?This page is about the new vaccines to prevent cervical cancer.
Vaccine - Wikipedia, the free encyclopedia
A vaccine is a preparation which is used to improve immunity to a particular disease. The term derives from Edward Jenner 's use of cowpox ("vacca" means cow in Latin), which, when ...
St George's Vaccine Institute Publications
Vaccine-related Publications. A dose-escalation Phase 1 clinical trial of immunogenicity and reactogenicity of live attenuated Shigella dysenteriaei icsA- toxA- ent- fep
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Definition: vaccine from Online Medical Dictionary
The Online Medical Dictionary is a searchable dictionary of definitions from medicine, science and technology.
Vaccine @ The Gallery - Turnmills
Vaccine residents The Viceroy and Ben Beaton host a night of up and coming trance music at The Gallery - Turnmills in London on friday nights.
HPV vaccine - Wikipedia, the free encyclopedia
Human papillomavirus (HPV) vaccine is a vaccine that targets certain strains of human papillomavirus associated with the development of cervical cancer and genital warts. [1] Two ...