Vaccination is the administration of antigenic material (a vaccine) to stimulate adaptive immunity to a disease. Vaccines can prevent or ameliorate the effects of infection by many pathogens. There is strong evidence for the efficacy of many vaccines, such as the influenza vaccine the HPV vaccine and the chicken pox vaccine among others. Vaccination is generally considered to be the most effective method of preventing infectious diseases. The material administered can either be live but weakened forms of pathogens (bacteria or viruses), killed or inactivated forms of these pathogens, or purified material such as proteins.
The word vaccination was first used by Edward Jenner in 1796. Louis Pasteur furthered the concept through his pioneering work in microbiology. Vaccination is so named because the first vaccine was derived from a virus affecting cows—the relatively benign cowpox virus—which provides a degree of immunity to smallpox, a contagious and deadly disease. In common speech, ‘vaccination’ and ‘immunization’ generally have the same colloquial meaning. This distinguishes it from inoculation which uses unweakened live pathogens, although in common usage either is used to refer to an immunization. The word “vaccination” was originally used specifically to describe the injection of smallpox vaccine
TYPES OF VACCINE
All vaccinations work by presenting a foreign antigen to the immune system in order to evoke an immune response, but there are several ways to do this. The four main types that are currently in clinical use are as follows:
- An inactivated vaccine consists of virus particles which are grown in culture and then killed using a method such as heat or formaldehyde. The virus particles are destroyed and cannot replicate, but the virus capsid proteins are intact enough to be recognized and remembered by the immune system and evoke a response. When manufactured correctly, the vaccine is not infectious, but improper inactivation can result in intact and infectious particles. Since the properly produced vaccine does not reproduce, booster shots are required periodically to reinforce the immune response.
- Virus-like particle vaccines consist of viral protein(s) derived from the structural proteins of a virus. These proteins can self-assemble into particles that resemble the virus from which they were derived but lack viral nucleic acid, meaning that they are not infectious. Because of their highly repetitive, multivalent structure, virus-like particles are typically more immunogenic than subunit vaccines (described below). The human papillomavirus and Hepatitis B virus vaccines are two virus-like particle-based vaccines currently in clinical use.
Immunization Schedule for Babies
|At Birth||BCG, OPV (0 dose), HepatitisB (1st dose)|
|6 weeks||DPT (1st dose), OPV (1st dose), HepatitisB (2nd dose)|
|10 weeks||DPT (2nd dose), OPV (2nd dose), HepatitisB (2nd dose)|
|14 weeks||DPT (3rd dose), OPV (3rd dose), HepatitisB (3rd dose)|
|9 – 12 months||Measles vaccine|
|15 – 18 months||DPT (4th dose), OPV (4th dose), MMR vaccine|
|10 years||TT, HepatitisB|
|Anthrax vaccine (BioThrax)||Puziss-Wright medium 1095, synthetic or semisynthetic||Aluminum Hydroxide, Amino Acids, Benzethonium Chloride, Formaldehyde
or Formalin, Inorganic Salts and Sugars, Vitamins
|BCG (Bacillus Calmette-Guérin) (Tice)||Synthetic or semisynthetic||Asparagine, Citric Acid, Lactose, Glycerin, Iron Ammonium Citrate,
Magnesium Sulfate, Potassium Phosphate
|DTaP (Daptacel)||Cohen-Wheeler or Stainer-Scholte media, synthetic or semisynthetic||Aluminum Phosphate, Ammonium Sulfate, Casamino Acid, Dimethyl-betacyclodextrin,
Formaldehyde or Formalin, Glutaraldehyde, 2-Phenoxyethanol
Immunity and herd immunity
Vaccination policies aim to produce immunity to preventable diseases. Besides individual protection from getting ill, with some vaccines policies aim also to provide herd immunity which is based on the idea that the pathogen will have trouble spreading when a significant part of the population has immunity against it.
Eradication of disease
With some vaccines, a goal of vaccination policies is to eradicate the disease – make it disappear from Earth altogether. The World Health Organization coordinated the global effort to eradicate smallpox globally Victory is also claimed for getting rid of endemic measles, mumps and rubella in Finland The last naturally occurring case of smallpox occurred in Somalia in 1977. In 1988, the governing body of WHO targeted polio for eradication by the year 2000, but didn’t succeed. The next eradication target would most likely be measles, which has declined since the introduction of measles vaccination in 1963.
Individual versus group goals
Rational individuals will attempt to minimize the risk of illness, and will seek vaccination for themselves or their children if they perceive a high threat of disease and a low risk to vaccination
Vaccine court is the popular term which refers to the Office of Special Masters of the U.S. Court of Federal Claims, which administers a no-fault system for litigating vaccine injury claims. These claims against vaccine manufacturers cannot normally be filed in state or federal civil courts, but instead must be heard in the Court of Claims, sitting without a jury. The program was established by the 1986 National Childhood Vaccine Injury Act (NCVIA), passed by the United States Congress in response to a threat to the vaccine supply due to a 1980s scare over the DPT vaccine. Despite the belief of most public health officials that claims of side effects were unfounded, large jury awards had been given to some plaintiffs, most DPT vaccine makers had ceased production, and officials feared the loss of herd immunity.
Some parents of children with autism spectrum disorders have attributed the disorders’ onset to vaccines, often citing the mercury-based preservative thiomersal as the cause, and have demanded compensation from vaccine makers. However, the mainstream medical and scientific communities have consistently found no link between routine childhood vaccines and autism.
International AIDS Vaccine Initiative
The International AIDS Vaccine Initiative (known as IAVI) is a global not-for-profit, public-private partnership working to accelerate the development of vaccines to prevent HIV infection and AIDS. IAVI researches and develops vaccine candidates, conducts policy analyses, serves as an advocate for the field and engages communities in the trial process and AIDS vaccine education. The organization takes a comprehensive approach to HIV and AIDS that supports existing HIV prevention and treatment programs while emphasizing the need for new AIDS prevention tools. It also works to ensure that future vaccines will be accessible to all who need them. The organization has offices in Africa, Europe, India and the United States.
IAVI’s scientific team, drawn largely from private industry, researches and develops AIDS vaccine candidates and engages in clinical trials and research through partnerships with more than 50 academic, biotechnology, pharmaceutical and governmental institutions. A major portion of the organization’s activities occur in developing countries, where 95 percent of new HIV infections occur. IAVI sponsors AIDS vaccine trials in collaboration with local scientists primarily in Africa and India, where subtypes of HIV different from that common in North America circulate.The organization also has provided resources to translational research to fill roles traditionally played by the biotechnology or biopharmaceutical companies
The UK Vaccination Acts of 1840, 1853 and 1898 reflect the continuing argument over vaccination policy in the United Kingdom. Similar legislation was passed in the USA and other countries.Alfred Russel Wallace gave an account of smallpox and vaccination in 1895 in which he characterized the historical policies into encouragement, compulsion, and penal compulsion.
– The 1840 Act
- Made variolation illegal.
- Provided optional vaccination free of charge.
In general, the disadvantages of variolation are the same as those of vaccination, but added to them is the generally agreement that variolation was always more dangerous than vaccination.
Vaccination was first made compulsory in 1853, and the provisions were made more stringent in 1867, 1871, and 1874.
– The 1853 Act
By the Act it was required:
- That every child, whose health permits, shall be vaccinated within three, or in case of orphanage within four mouths of birth, by the public vaccinator of the district, or by some other medical practitioner.
- That notice of this requirement, and information as to the local arrangements for public vaccination, shall, whenever a birth is registered, be given by the register of births to the parents or guardians of the child.
ADJUVANTS AND PRESERVATIVES
- Vaccines typically contain one or more adjuvants, used to boost the immune response. Tetanus toxoid, for instance, is usually adsorbed onto alum. This presents the antigen in such a way as to produce a greater action than the simple aqueous tetanus toxoid. People who get an excessive reaction to adsorbed tetanus toxoid may be given the simple vaccine when time for a booster occurs.
- In the preparation for the 1990 Gulf campaign, Pertussis vaccine (not acellular) was used as an adjuvant for Anthrax vaccine. This produces a more rapid immune response than giving only the Anthrax, which is of some benefit if exposure might be imminent.
- They may also contain preservatives, which are used to prevent contamination with bacteria or fungi. Until recent years, the preservative thiomersal was used in many vaccines that did not contain live virus. As of 2005, the only childhood vaccine in the U.S. that contains thiomersal in greater than trace amounts is the influenza vaccine which is currently recommended only for children with certain risk factors. Single-dose Influenza vaccines supplied in the UK do not list Thiomersal (its UK name) in the ingredients. Preservatives may be used at various stages of production of vaccines, and the most sophisticated methods of measurement might detect traces of them in the finished product, as they may in the environment and population as a whole.
- Inoculation was developed in ancient China. Scholar Ole Lund comments: “The earliest documented examples of vaccination are from India and China in the 17th century, where vaccination with powdered scabs from people infected with smallpox was used to protect against the disease. Smallpox used to be a common disease throughout the world and 20% to 30% of infected persons died from the disease. Smallpox was responsible for 8% to 20% of all deaths in several European countries in the 18th century. The tradition of inoculation may have originated in India in 1000 BCE The mention of inoculation in theSact’eya Grantham, an Ayurvedic text, was noted by the French scholar Henri Marie Husson in the journal Dictionaire des sciences me`dicales. Almroth Wright, the professor of pathology at Netley, further helped shape the future of vaccination by conducting limited experiments on the professional staff at Netly, including himself. The outcome of these experiments resulted in further development of vaccination in Europe. The Anatolian Ottoman Turks knew about methods of inoculation.This kind of inoculation and other forms of variolation were introduced into England by Lady Montagu, a famous English letter-writer and wife of the English ambassador at Istanbul between 1716 and 1718, who’d almost died from smallpox as a young adult and was physically scarred from it.
TRIGGERING IMMUNE SENSITIZATION
Some modern vaccines are administrated after the patient already has contracted a disease, as in the case of experimental AIDS ,cancerand alzheimer’ disease vaccines .
Vagina given after exposure to small pox , within the first hour days , is reported to attenuate the disease considerbaly and vaccination within the first week is known to be benificial to a degree .
DIFFERENCE BETWEEN VACCINATION AND INOCULATION
Many times this words are used interchangeably , as if they were synonyms . infact they are different things .
As Doctor Byron plant explains: “ vaccination is the more commonly used term whish actually consists of a “safe” injection of a sample taken from a cow suffering from cow pox …… Inoculation ,a practice probably as old as the disease itself, is the injection of the variola virus taken from a pustule or scab of a small pox sufferer into the superficial layers of the skin , commonly on the upper arm of the subject .