Vaccine | Health Dictionary

A preparation of dead particulate or weakened bacteria or viruses prepared for injection into the body so that antibodies are formed to prevent disease (eg polio). Detoxi fied but genetically potent toxins (called toxoids) can also be used (e.g. tetanus and diphtheria)
The name applied generally to dead or attenuated living infectious material introduced into the body, with the object of increasing its power to resist or to get rid of a disease. (See also IMMUNITY.)

Healthy people are inoculated with vaccine as a protection against a particular disease; this produces ANTIBODIES which will confer immunity against a subsequent attack of the disease. (See IMMUNISATION for programme of immunisation during childhood.)

Vaccines may be divided into two classes: stock vaccines, prepared from micro-organisms known to cause a particular disease and kept in readiness for use against that disease; and autogenous vaccines, prepared from microorganisms which are already in the patient’s body and to which the disease is due. Vaccines intended to protect against the onset of disease are of the former variety.

Autogenous vaccines are prepared by cultivating bacteria found in SPUTUM, URINE and FAECES, and in areas of in?ammation such as BOILS (FURUNCULOSIS). This type of vaccine was introduced by Wright about 1903.

Anthrax vaccine was introduced in 1882 for the protection of sheep and cattle against this disease. A safe and e?ective vaccine for use in human beings has now been evolved. (See ANTHRAX.)

BCG vaccine is used to provide protection against TUBERCULOSIS. (See also separate entry on BCG VACCINE.)

Cholera vaccine was introduced in India about 1894. Two injections are given at an interval of at least a week; this gives a varying degree of immunity for six months. (See CHOLERA.)

Diphtheria vaccine is available in several forms. It is usually given along with tetanus and pertussis vaccine (see below) in what is known as TRIPLE VACCINE. This is given in three doses: the ?rst at the age of two months; the second at three months; and the third at four months, with a booster dose at the age of ?ve years. (See DIPHTHERIA.)

Hay fever vaccine is a vaccine prepared from the pollen of various grasses. It is used in gradually increasing doses for prevention of HAY FEVER in those susceptible to this condition.

In?uenza vaccine A vaccine is now available for protection against INFLUENZA due to the in?uenza viruses A and B. Its use in Britain is customarily based on advice from the health departments according to the type of in?uenza expected in a particular year.

Measles, mumps and rubella (MMR) vaccines are given in combination early in the second year of life. A booster dose may prove necessary, as there is some interference between this vaccine and the most recent form of pertussis vaccine (see below) o?ered to children. Uptake has declined a little because of media reports suggesting a link with AUTISM – for which no reliable medical evidence (and much to the contrary) has been found by investigating epidemiologists. (See also separate entry for each disease, and for MMR VACCINE.)

Pertussis (whooping-cough) vaccine is prepared from Bordetella pertussis, and is usually given along with diphtheria and tetanus in what is known as triple vaccine. (See also WHOOPING-COUGH.)

Plague vaccine was introduced by Ha?kine, and appears to give useful protection, but the duration of protection is relatively short: from two to 20 months. Two injections are given at an interval of four weeks. A reinforcing dose should be given annually to anyone exposed to PLAGUE.

Poliomyelitis vaccine gives a high degree of protection against the disease. This is given in the form of attenuated Sabin vaccine which is taken by mouth – a few drops on a lump of sugar. Reinforcing doses of polio vaccine are recommended on school entry, on leaving school, and on travel abroad to countries where POLIOMYELITIS is ENDEMIC.

Rabies vaccine was introduced by Pasteur in 1885 for administration, during the long incubation period, to people bitten by a mad dog, in order to prevent the disease from developing. (See RABIES.)

Rubella vaccine, usually given with mumps and measles vaccine in one dose – called MMR VACCINE, see also above – now provides protection against RUBELLA (German measles). It also provides immunity for adolescent girls who have not had the disease in childhood and so ensures that they will not acquire the disease during any subsequent pregnancy – thus reducing the number of congenitally abnormal children whose abnormality is the result of their being infected with rubella via their mothers before they were born.

Smallpox vaccine was the ?rst introduced. As a result of the World Health Organisation’s successful smallpox eradication campaign – it declared the disease eradicated in 1980 – there is now no medical justi?cation for smallpox vaccination. Recently, however, there has been increased interest in the subject because of the potential threat from bioterrorism. (See also VACCINATION.)

Tetanus vaccine is given in two forms: (1) In the so-called triple vaccine, combined with diphtheria and pertussis (whooping-cough) vaccine for the routine immunisation of children (see above). (2) By itself to adults who have not been immunised in childhood and who are particularly exposed to the risk of TETANUS, such as soldiers and agricultural workers.

Typhoid vaccine was introduced by Wright and Semple for the protection of troops in the South African War and in India. TAB vaccine, containing Salmonella typhi (the causative organism of typhoid fever – see ENTERIC FEVER) and Salmonella paratyphi A and B (the organisms of paratyphoid fever – see ENTERIC FEVER) has now been replaced by typhoid monovalent vaccine, containing only S. typhi. The change has been made because the monovalent vaccine is less likely to produce painful arms and general malaise, and there is no evidence that the TAB vaccine gave any protection against paratyphoid fever. Two doses are given at an interval of 4–6 weeks, and give protection for 1–3 years.



Vaccine | Health Dictionary

Keywords of this word: Vaccine


BCG VACCINE

Medical Dictionary

BCG (Bacillus Calmette-Guérin) vaccine, which was ?rst introduced in France in 1908, is the only vaccine that has produced signi?cant immunity against the tubercle bacillus (see TUBERCULOSIS) and at the same time has proved safe enough for use in human subjects. BCG vaccination is usually considered for the following groups of people. (1) Schoolchildren: the routine programme in schools usually covers children aged between ten and 14. (2) Students, including those in teacher training colleges. (3) Immigrants from countries with a high prevalence of tuberculosis (TB). (4) Children and newborn infants born in the UK to parents from Group 3, or other newborns at parents’ request. (5) Health workers, such as nurses, and others likely to be exposed to infection in their work. (6) Veterinary workers who handle animals susceptible to TB. (7) Sta? of prisons, residential homes and hostels for refugees and the homeless. (8) Household contacts of people known to have active TB and newborn infants in households where there is a history of the disease. (9) Those staying for more than one month in high-risk countries.

A pre-vaccination tuberculin test is necessary in all age-groups except newborn infants, and only those with negative tuberculin reactions are vaccinated. Complications are few and far between. A local reaction at the site of vaccination usually occurs between two and six weeks after vaccination, beginning as a small papule that slowly increases in size. It may produce a small ulcer. This heals after around two months, leaving a small scar. (See IMMUNITY; TUBERCULIN.)... Medical Dictionary

DPT VACCINE

Medical Dictionary

Often called the TRIPLE VACCINE, the injections produce immunity against DIPHTHERIA, whooping cough (PERTUSSIS) and TETANUS. The vaccine is given as a course of three injections to infants around the ages of two, three and four months, together with haemophilus in?uenza B and meningococcal C vaccine as well as oral polio vaccine. A booster injection is given at school entry (see schedule in IMMUNISATION).... Medical Dictionary

MMR VACCINE

Medical Dictionary

A combined vaccine o?ering protection against MEASLES, MUMPS and RUBELLA (German measles), it was introduced in the UK in 1988 and has now replaced the measles vaccine. The combined vaccine is o?ered to all infants in their second year; health authorities have an obligation to ensure that all children have received the vaccine by school entry – it should be given with the pre-school booster doses against DIPHTHERIA, TETANUS and POLIOMYELITIS, if not earlier – unless there is a valid contra-indication (such as partial immunosuppression), parental refusal, or evidence of previous infection. MMR vaccine may also be used in the control of measles outbreaks, if o?ered to susceptible children within three days of exposure to infection. The vaccine is e?ective and generally safe, though minor symptoms such as malaise, fever and rash may occur 5–10 days after immunisation. The incidence of all three diseases has dropped substantially since MMR was introduced in the UK and USA.

A researcher has suggested a link between the vaccine and AUTISM, but massive studies of children with and without this condition in several countries have failed to ?nd any evidence to back the claim. Nonetheless, the publicity war has been largely lost by the UK health departments so that vaccine rates have dropped to a worryingly low level.

(See IMMUNISATION.)... Medical Dictionary

SABIN VACCINE

Medical Dictionary

Introduced in 1962, the attenuated live oral vaccine (Sabin) against POLIOMYELITIS replaced the previous inactivated vaccine introduced in 1956 (see SALK VACCINE).... Medical Dictionary

SALK VACCINE

Medical Dictionary

A vaccine obtained by treating the POLIOMYELITIS virus with formalin. This prevents the virus from causing the disease but allows it to stimulate the production of ANTIBODIES. Salk vaccine is given by injection and protects the recipient against the disease. (See also IMMUNISATION.)... Medical Dictionary

TAB VACCINE

Medical Dictionary

A combined VACCINE administered to produce IMMUNITY against typhoid and paratyphoid A and B (see ENTERIC FEVER). (See also IMMUNISATION.)... Medical Dictionary

TRIPLE VACCINE

Medical Dictionary

Also known as DPT vaccine, this is an injection that provides IMMUNITY against DIPHTHERIA, pertussis (whooping-cough) and TETANUS. It is given as a course of three injections at around the ages of two, three and four months. A booster dose of diphtheria and tetanus is given at primary-school age. Certain infants – those with a family history of EPILEPSY, or who have neurological disorders or who have reacted severely to the ?rst dose – should not have the pertussis element of DPT. (See MMR VACCINE; IMMUNISATION.)... Medical Dictionary

YELLOW FEVER VACCINE IS PREPARED FROM

Medical Dictionary

chick embryos injected with the living, attenuated strain (17D) of pantropic virus. Only one injection is required, and immunity persists for many years. Re-inoculation, however, is desirable every ten years. (See YELLOW FEVER.)

Haemophilus vaccine (HiB) This vaccine was introduced in the UK in 1994 to deal with the annual incidence of about 1,500 cases and 100 deaths from haemophilus MENINGITIS, SEPTICAEMIA and EPIGLOTTITIS, mostly in pre-school children. It has been remarkably successful when given as part of the primary vaccination programme at two, three and four months of age – reducing the incidence by over 95 per cent. A few cases still occur, either due to other subgroups of the organism for which the vaccine is not designed, or because of inadequate response by the child, possibly related to interference from the newer forms of pertussis vaccine (see above) given at the same time.

Meningococcal C vaccine Used in the UK from 1998, this has dramatically reduced the incidence of meningitis and septicaemia due to this organism. Used as part of the primary programme in early infancy, it does not protect against other types of meningococci.

Varicella vaccine This vaccine, used to protect against varicella (CHICKENPOX) is used in a number of countries including the United States and Japan. It has not been introduced into the UK, largely because of concerns that use in infancy would result in an upsurge in cases in adult life, when the disease may be more severe.

Pneumococcal vaccine The pneumococcus is responsible for severe and sometimes fatal childhood diseases including meningitis and septicaemia, as well as PNEUMONIA and other respiratory infections. Vaccines are available but do not protect against all strains and are reserved for special situations – such as for patients without a SPLEEN or those who are immunode?cient.... Medical Dictionary