Citizendia
Your Ad Here

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 administered to humans, provided them protection against smallpox, the work which Louis Pasteur and others carried on. Edward Jenner, FRS, ( May 17 1749 – January 26 1823) was an English scientist who studied his natural surroundings in Berkeley Cowpox is a Disease of the skin that is caused by a Virus known as the Cowpox virus. Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. Human beings, humans or man (Origin 1590–1600 L homō man OL hemō the earthly one (see Humus Smallpox is an Infectious disease unique to humans caused by either of two virus variants named Variola major and Variola minor. Louis Pasteur (27 December 1822 – 28 September 1895 a French Chemist and Microbiologist, is best known for remarkable breakthroughs in the causes and Vaccines are based on the concept of variolation originating in China, in which a person is deliberately infected with a weak form of smallpox. Inoculation is the placement of something to where it will grow or reproduce and is most commonly used in respect of the introduction of a serum Vaccine, or antigenic substance 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. Vaccination is the administration of Antigenic material (the Vaccine) to produce immunity to a disease Since vaccination was much safer, smallpox inoculation fell into disuse and was eventually banned in England in 1849.

Vaccines can be prophylactic (e. Prophylaxis ( Greek "προφυλάσσω" to guard or prevent beforehand) is any medical or Public health procedure whose purpose g. to prevent or ameliorate the effects of a future infection by any natural or "wild" pathogen), or therapeutic (e. An infection is the detrimental Colonization of a host Organism by a foreign Species. A pathogen (from Greek πάθος pathos "suffering passion" and γἰγνομαι (γεν- gignomai (gen- "I give birth to" infectious Medication, also referred to as medicine, can be loosely defined as any substance intended for use in the diagnosis cure mitigation treatment or prevention of disease g. vaccines against cancer are also being investigated; see cancer vaccine). The term cancer vaccine refers to a Vaccine that either prevents infections with cancer-causing viruses or treats existing Cancer.

Contents

Types

Avian Flu vaccine development by reverse genetics techniques.
Avian Flu vaccine development by reverse genetics techniques. For the H5N1 subtype of Avian influenza see H5N1. Avian influenza, sometimes Avian flu, and commonly Bird flu refers Reverse genetics is an approach to discovering the function of a Gene that proceeds in the opposite direction of so called forward genetic screens of Classical

Vaccines may be dead or inactivated organisms or purified products derived from them.

There are four types of traditional vaccines[1]:

A number of innovative vaccines are also in development and in use:

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. A synthetic vaccine is a Vaccine consisting mainly of synthetic Peptides, Carbohydrates or Antigens They are usually considered to be safer than

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 body recognises the protein coat on the virus, and thus is 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. Virulence (also called pestiferousness) refers to the degree of Pathogenicity of a Microbe, or in other words the relative ability of a Microbe

Vaccines have contributed to the eradication of smallpox, one of the most contagious and deadly diseases known to man. Smallpox is an Infectious disease unique to humans caused by either of two virus variants named Variola major and Variola minor. Other diseases such as rubella, polio, measles, mumps, chickenpox, and typhoid are nowhere near as common as they were just a hundred years ago. Rubella, commonly known as German measles, is a Disease caused by Rubella virus Poliomyelitis, often called polio or infantile paralysis, is an acute viral Infectious disease spread from person to person primarily via Measles (rubeola is a Disease caused by a virus specifically a Paramyxovirus of the genus Morbillivirus. Mumps or epidemic Parotitis is a Viral disease of the Human species Chickenpox is a highly contagious illness caused by primary infection with Varicella zoster virus (VZV Typhoid fever, also known as enteric fever, bilious fever, Yellow Jack or commonly just typhoid, is an illness caused by the Bacterium 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. Herd immunity (or community immunity) describes a type of immunity that occurs when the Vaccination of a portion of the Population (or herd Polio, which is transmitted only between humans, is targeted by an extensive eradication campaign that has seen endemic polio restricted to only parts of four countries. The global eradication of poliomyelitis is a Public health effort to eliminate all cases of Poliomyelitis (polio infection [2] The difficulty of reaching all children as well as cultural misunderstandings, however, have caused the eradication date to be missed several times.

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'. A vaccination schedule is a recommended series of Vaccinations including the suggested timing of all doses Vaccination policy refers to the policy a government adopts in relation to Vaccination. 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, HiB, chicken pox, rotavirus, influenza, meningococcal disease and pneumonia. The Advisory Committee on Immunization Practices (ACIP provides advice and guidance on effective control of Vaccine -preventable Diseases in the U The Centers for Disease Control and Prevention (or CDC) is an agency of the United States Department of Health and Human Services based in unincorporated Hepatitis A, (formerly known as infectious hepatitis) is an acute Infectious disease of the Liver caused by Hepatitis A virus which is Poliomyelitis, often called polio or infantile paralysis, is an acute viral Infectious disease spread from person to person primarily via Mumps or epidemic Parotitis is a Viral disease of the Human species Measles (rubeola is a Disease caused by a virus specifically a Paramyxovirus of the genus Morbillivirus. Rubella, commonly known as German measles, is a Disease caused by Rubella virus Diphtheria ( Greek διφθερα ( diphthera)—“pair of leather scrolls" is an upper respiratory tract illness characterized by sore Pertussis, also known as whooping cough, is a highly contagious Disease caused by the Bacterium Bordetella pertussis; it derived its Tetanus is a medical condition that is characterized by a prolonged contraction of Skeletal muscle fibres Haemophilus influenzae, formerly called Pfeiffer's bacillus or Bacillus influenzae, is a non-motile Gram-negative Coccobacillus Chickenpox is a highly contagious illness caused by primary infection with Varicella zoster virus (VZV Rotavirus is a Genus of Double-stranded RNA virus in the family Reoviridae. Meningococcal disease describes infections caused by Neisseria meningitidis (also termed meningococcus and carries a high mortality rate if untreated Pneumonia is an inflammatory illness of the Lung. Frequently it is described as lung Parenchyma / alveolar inflammation and abnormal 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. Pneumococcal conjugate vaccine or Prevnar is a Vaccine used to protect Infants and young children against disease caused by the Bacterium The MMRV vaccine combines the Attenuated virus MMR ( Measles, Mumps, Rubella) vaccine with the addition of Chickenpox Vaccine

Besides recommendations for infant vaccinations and boosters, many specific vaccines are recommended at other ages or for repeated injections throughout life -- most commonly for measles, tetanus, influenza, and pneumonia. Pregnant women are often screened for continued resistance to rubella. The human papillomavirus vaccine is currently recommended in the U. A human papillomavirus ( HPV) is a Papillomavirus that infects the skin and Mucous membranes of Humans Approximately 130 HPV types have been S. and UK for ages 9–25. Vaccine recommendations for the elderly concentrate on pneumonia and influenza, which are more deadly to that group. In 2006, a vaccine was introduced against shingles, a disease caused by the chicken pox virus, which usually affects the elderly. Herpes zoster (or simply zoster) commonly known as shingles, is a Viral disease characterized by a painful skin rash with Blisters in a limited

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. For a topic outline on this subject see List of basic Australia topics. 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. Country to "Dominion of Canada" or "Canadian Federation" or anything else please read the Talk Page ) 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.

Efficacy

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.

Adjuvants are typically used to boost immune response. In Immunology, an adjuvant is an agent that may stimulate the Immune system and increase the response to a Vaccine, without having any specific Antigenic Adjuvants are sometimes called the dirty little secret of vaccines [3] 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. Squalene is a natural Organic compound originally obtained for commercial purposes primarily from Shark liver oil, though there are botanic sources as well including The efficacy or performance of the vaccine is dependent on a number of factors:

When a vaccinated individual does develop the disease vaccinated against, the disease is likely to be milder than without vaccination. Vaccine efficacy is defined as the reduction in the incidence of a disease among people who have received a Vaccine compared to the incidence in unvaccinated people A vaccination schedule is a recommended series of Vaccinations including the suggested timing of all doses

The following are important considerations in the effectiveness of a vaccination program:

  1. careful modelling to anticipate the impact that an immunisation campaign will have on the epidemiology of the disease in the medium to long term
  2. ongoing surveillance for the relevant disease following introduction of a new vaccine and
  3. maintaining high immunisation rates, even when a disease has become rare.

Vaccine developments

Rational attenuation

Specific modifications or deletions of genes that confer virulence removes the pathogenicity of the microbe whilst still allowing an immune response to be generated. This type of rational attenuation can be viewed as creating a live, attenuated vaccine.

Vector-mediated subunit delivery

Introducing a non-infectious, non-pathogenic subunit into a live vector can prompt an immune response without presence of the pathogen. For example, rabies surface protein gene has been inserted into vaccinia virus.

Virus-like particles

Capsid proteins of icosohedral viruses assemble without the prescence of a genome. They are antigenically authentic, but non-infectious. This has been used for HPV-16 and HPV-18.

Controversy

Main article: Vaccine controversy

Opposition to vaccination, from a wide array of vaccine critics, has existed since the earliest vaccination campaigns. A vaccine controversy is a dispute over the morality ethics effectiveness or safety of Vaccination. A vaccine controversy is a dispute over the morality ethics effectiveness or safety of Vaccination. [1] Disputes have arisen over the morality, ethics, effectiveness, and safety of vaccination. The mainstream medical opinion is that the benefits of preventing suffering and death from serious infectious diseases greatly outweigh the risks of rare adverse effects following immunization. An infectious disease is a clinically evident Disease resulting from the presence of Pathogenic microbial agents including Pathogenic viruses Pathogenic In Medicine, an adverse effect is a harmful and undesired effect resulting from a medication or other intervention such as Chemotherapy or Surgery. Immunization, or immunisation, is the process by which an individual's Immune system becomes fortified against an agent (known as the [2][3] Some vaccination critics say that vaccines are ineffective against disease[4] or that vaccine safety studies are inadequate. [3][4] Some religious groups oppose vaccination as a matter of doctrine,[5] and some political groups oppose mandatory vaccination on the grounds of individual liberty. Doctrine (Latin doctrina) is a codification of beliefs or "a body of teachings quot or "instructions" taught principles or positions as the Liberty, the freedom to act or believe without being stopped by unnecessary force [1]

Economics of 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. Human immunodeficiency virus ( HIV) is a Lentivirus (a member of the Retrovirus family that can lead to acquired immunodeficiency syndrome Malaria is a vector -borne Infectious disease caused by Protozoan Parasites It is widespread in tropical and subtropical regions including Tuberculosis (abbreviated as TB for tubercle bacillus or T u' b' erculosis Bacillus --> is a common 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, universities and non-profit organizations.

Many researchers and policymakers are calling for a different approach, using 'pull' mechanisms to motivate industry. Mechanisms such as prizes, tax credits, or advance market commitments could ensure a financial return to firms that successfully developed a HIV vaccine. An advance market commitment is a binding contract typically offered by a Government or other financial entity used to guarantee a viable market if a Vaccine or 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 UK 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 and improved home and work environments, all of which occurred during the same period.

Intellectual property

Intellectual property can also be viewed as an obstacle to the development of new vaccines. Intellectual property ( IP) is a legal field that refers to creations of the mind such as musical literary and artistic works inventions and symbols names Because of the weak protection offered through the patent of the final product, the protection of the innovation regarding vaccines is often made through the patent of processes used on the development of new vaccines as well as the protection of secrecy. A patent is a set of Exclusive rights granted by a State to an inventor or his assignee for a fixed period of time in exchange for a disclosure of an A patent is a set of Exclusive rights granted by a State to an inventor or his assignee for a fixed period of time in exchange for a disclosure of an [6]

Preservatives

Many vaccines need preservatives to prevent serious adverse effects such as the Staphylococcus infection that in one 1928 incident killed 12 of 21 children inoculated with a diphtheria vaccine that lacked a preservative. Staphylococcus (in Greek σταφυλη staphyle means bunch of grapes and κοκκος coccos means granule is a genus of Gram-positive Diphtheria ( Greek διφθερα ( diphthera)—“pair of leather scrolls" is an upper respiratory tract illness characterized by sore [7] Several preservatives are available, including thiomersal, 2-phenoxyethanol, and formaldehyde. Thiomersal ( INN) (C9H9HgNaO2S commonly known in the United States as thimerosal, is an Organomercury compound (approximately Phenoxyethanol is an organic chemical compound, a Glycol ether often used in Dermatological products such as skin creams Formaldehyde is a Chemical compound with the formula H2CO It is the simplest Aldehyde —an organic compound containing a terminal Carbonyl Thiomersal is more effective against bacteria, has better shelf life, and improves vaccine stability, potency, and safety, but in the U. S. , the European Union, and a few other affluent countries, it is no longer used as a preservative in childhood vaccines, as a precautionary measure due to its mercury content. The European Union ( EU) is a political and economic union of twenty-seven member states, located primarily in Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum [8] Controversial claims have been made that thiomersal contributes to autism; no convincing scientific evidence supports these claims. The thiomersal controversy is between claims that Thiomersal -containing Vaccines (TCVs cause or contribute to the development of Autism and other Language development. The terminology [9]

Delivery systems

There are several new delivery systems in development, which will hopefully make vaccines more efficient to deliver. Possible methods include liposomes and ISCOM[10] (immune stimulating complex). A liposome is a tiny bubble ( vesicle) made out of the same material as a cell membrane.

Plasmids

The use of plasmids has been validated in preclinical studies as a protective vaccine strategy for cancer and infectious diseases. A plasmid is an extra-chromosomal DNA molecule separate from the chromosomal DNA which is capable of replicating independently of the chromosomal DNA However, the crossover application into human studies has been met with poor results based on the inability to provide clinically relevant benefit. The overall efficacy of plasmid DNA immunization depends on increasing the plasmid's immunogenicity while also correcting for factors involved in the specific activation of immune effector cells. [11]

Use in nonhumans

See also: Influenza vaccine#Flu vaccine for nonhumans and Vaccination of dogs

Vaccinations of animals are used both to prevent their contracting diseases and to prevent transmission of disease to humans. A Vaccine is an Inoculation designed to increase immunity against a specific disease Programs supporting regular vaccination of dogs have contributed both to the health of dogs and to the Public health. Both animals kept as pets and animals raised as stock are vaccinated. In some instances, wild populations may be vaccinated. This is sometimes accomplished with vaccine-laced food spread in a disease-prone area and has been used to attempt to control rabies in raccoons. Rabies (from rabies “madness rage fury” Also known as “ hydrophobia ” is a viral Zoonotic neuroinvasive disease that The raccoon ( Procyon lotor) (sometimes spelt as racoon) also known as the common raccoon, North American raccoon, northern raccoon

Where rabies occurs, rabies vaccination of dogs may be required by law. Other canine vaccines include canine distemper, canine parvovirus, canine hepatitis virus, adenovirus-2, leptospirosis, bordatella, canine parainfluenza virus, and Lyme disease among others. Canine distemper is a very serious viral Disease affecting animals in the families Canidae, Mustelidae, Mephitidae, Hyaenidae Canine parvovirus type 2 ( CPV2, colloquioally parvo) is a Contagious Virus mainly affecting Dogs. Infectious canine hepatitis is an acute liver infection in dogs caused by canine adenovirus type-1 (CAV-1 Leptospirosis (also known as Weil's disease, canicola fever, canefield fever, nanukayami fever, 7-day fever and many more is a Bordetella is a Genus of small (02 - 07 µm Gram-negative coccobacilli of the phylum Proteobacteria. Lyme disease, or borreliosis, is an Emerging infectious disease caused by at least three Species of Bacteria belonging to the Genus

See also

References

  1. ^ a b Wolfe R, Sharp L (2002). Immunology is a broad branch of biomedical Science that covers the study of all aspects of the Immune system in all Organisms It deals with Immunization, or immunisation, is the process by which an individual's Immune system becomes fortified against an agent (known as the Inoculation is the placement of something to where it will grow or reproduce and is most commonly used in respect of the introduction of a serum Vaccine, or antigenic substance TA-CD is an active Vaccine developed by the Xenova Group which is used to negate the effects of Cocaine, making it suitable for use in treatment of Addiction Cocaine ( benzoylmethyl ecgonine) is a Crystalline Tropane Alkaloid that is obtained from the leaves of the Coca plant Jim was a former milk wagon horse who was used to produce serum containing antibodies against diphtheria toxin. A virosome is a unilamellar phospholipid bilayer vesicle with a mean diameter of 150 nm Vaccination is the administration of Antigenic material (the Vaccine) to produce immunity to a disease This is a list of Vaccine -related topics People Developers of vaccines Thomas Francis Jr "Anti-vaccinationists past and present". BMJ 325 (7361): 430–2. doi:10.1136/bmj.325.7361.430. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 12193361.  
  2. ^ Bonhoeffer J, Heininger U (2007). "Adverse events following immunization: perception and evidence". Curr Opin Infect Dis 20 (3): 237–46. doi:10.1097/QCO.0b013e32811ebfb0. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 17471032.  
  3. ^ a b Demicheli V, Jefferson T, Rivetti A, Price D (2005). "Vaccines for measles, mumps and rubella in children". Cochrane Database Syst Rev 19 (4). doi:10.1002/14651858.CD004407.pub2. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 16235361. Lay summary – Cochrane press release (PDF) (2005-10-19). Year 2005 ( MMV) was a Common year starting on Saturday (link displays full calendar of the Gregorian calendar. Events 202 BCE - The Battle of Zama results in the defeat of Carthage and Hannibal.  
  4. ^ a b Halvorsen R (2007). The Truth about Vaccines. Gibson Square. ISBN 9781903933923.  
  5. ^ White AD (1896). "Theological opposition to inoculation, vaccination, and the use of anæsthetics", A History of the Warfare of Science with Theology in Christendom. New York: Appleton. Retrieved on 2007-08-17. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 986 - A Byzantine army was destroyed in the pass of Trajan's Gate by the Bulgarians under the Comitopuli  
  6. ^ Hardman Reis T (2006). "The role of intellectual property in the global challenge for immunization". J World Intellect Prop 9 (4): 413–25. doi:10.1111/j.1422-2213.2006.00284.x. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
  7. ^ Thimerosal in vaccines. Center for Biologics Evaluation and Research, U. S. Food and Drug Administration (2007-09-06). Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 3114 BC - According to the Proleptic Julian calendar the current era in the Maya Long Count Calendar started Retrieved on 2007-10-01. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 331 BC - Alexander the Great defeats Darius III of Persia in the Battle of Gaugamela.
  8. ^ Bigham M, Copes R (2005). "Thiomersal in vaccines: balancing the risk of adverse effects with the risk of vaccine-preventable disease". Drug Saf 28 (2): 89–101. PMID 15691220.  
  9. ^ Offit PA (2007). Paul A Offit, MD, is a Pediatrician specializing in Infectious diseases an internationally known expert on Vaccines Immunology, "Thimerosal and vaccines—a cautionary tale". N Engl J Med 357 (13): 1278–9. doi:10.1056/NEJMp078187. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 17898096.  
  10. ^ Advanced Drug Delivery Reviews, 2004 (Vol. 56) (No. 10) 1367-1382 Morein, B. , Hu KeFei, Abusugra, I
  11. ^ Lowe et al (2008). "Plasmid DNA as Prophylactic and Therapeutic vaccines for Cancer and Infectious Diseases", Plasmids: Current Research and Future Trends. Caister Academic Press. ISBN 978-1-904455-35-6.  

External links

Dictionary

vaccine

-noun

  1. (immunology) A substance given to stimulate the body's production of antibodies and provide immunity against a disease, prepared from the agent that causes the disease, or a synthetic substitute.
© 2009 citizendia.org; parts available under the terms of GNU Free Documentation License, from http://en.wikipedia.org
 Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic