Immunise Australia Program
Australian Government Department of Health and Ageing
Australian Government Department of Health and Ageing. Immunise Australia Program. Information Line 1800 671 811
Immunise Australia Program. Information Line 1800 671 811

Glossary

Definitions of terms used throughout the Immunise Australia Program website.


For more technical information about vaccines and immunisation, please refer to the Australian Immunisation Handbook 9th Edition 2008 (NHMRC).


A B | C D | E F | G H I | J K L | M N O | P Q R S | T U V | W X Y Z


A B



Adjuvant


A preparation which may be added to a vaccine to improve the immune response to the vaccine.

ADT


The diphtheria and tetanus vaccine for adults. Also known as dT.

Adverse event following immunisation (AEFI)


An unwanted or unexpected event after a vaccine is given, which may be caused by the vaccine, or may occur by chance after immunisation. Adverse events may be at the site of the injection, or be a general illness or allergic reaction.

Anaphylaxis


A sudden and severe allergic reaction, which results in a serious fall in blood pressure, and may cause unconsciousness and death if not treated immediately.

Attenuation


The process of changing a virus or bacteria to reduce its disease-causing ability while retaining its ability to bring about a strong immune response in a person’s body.

Bacteria (singular Bacterium)


Micro-organisms (small living organisms that can only be seen with a microscope) smaller than a blood cell but bigger than a virus. Examples of infections caused by bacteria are diphtheria, tetanus, pertussis and Hib.

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C D



Carrier


A person who has an infection which, although not necessarily causing symptoms, may still be active and may spread to others; the carrier state may last for years; an example of infections that can result in the carrier state is hepatitis B.

Combination vaccine


A vaccine that contains more than one component designed to immunise against two or more diseases (e.g. dTPa, MMR or dTPa-HepB-Polio-Hib).

Conjugate


Some bacterial vaccines (eg. Hib and pneumococcal conjugate vaccines) are made from the chemical linking (conjugation) of a tiny amount of the ‘sugar’ (correctly known as the polysaccharide) that makes up the cell coat of the bacteria with a protein molecule, in order to improve the immune response to the vaccine.

Contraindication


A reason why a vaccine or drug must not be given.

Corticosteroid


A drug used to reduce inflammation and other immune responses.

dT


The diphtheria-tetanus vaccine for use in adults. Also known as ADT.

DTPa


A vaccine that protects against diphtheria, tetanus and pertussis (whooping cough). The acronym DTPa, using capital letters, signifies child formulations of diphtheria, tetanus and acellular pertussis-containing vaccines. These child formulations contain substantially larger amounts of diphtheria toxoid and pertussis antigens than adolescent/adult formulations.

dTpa


Adolescent/adult formulation The diphtheria-tetanus -acellular pertussis vaccine. dTpa contains substantially smaller amounts of diphtheria toxoid and pertussis antigens than the child formulations (which are signified by using all capital letters (DTPa)).

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E F



Encephalitis


Inflammation of the brain.

Encephalopathy


A general term to describe a variety of illnesses that affect the brain, including encephalitis.

Endemic


Endemic infections are present all the time in a community.

Epidemic


An epidemic is the occurrence in a community or region of an illness or disease in excess of normal expectancy within a given time period.

Febrile


Related to a fever (higher than normal temperature), as in febrile illness and febrile convulsions.

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G H I



HAV


Abbreviation for hepatitis A virus, the cause of infectious hepatitis, a common infection in travellers to developing countries.

HBsAg


Hepatitis B surface antigen which is found in the blood of a person who is a carrier of active hepatitis B virus infection.

HBV


Abbreviation for hepatitis B virus, a virus that is spread in various ways including blood-to-blood contact through sharing injection equipment and by sexual intercourse.

Hepatitis


Inflammation of the liver; can be caused by viruses e.g. hepatitis A and hepatitis B.

Herpes zoster infection (shingles)


This illness is caused by reactivation of the varicella-zoster virus, the virus that causes varicella (chickenpox). The virus remains in the nerve cells for a long time after recovery from varicella. As immunity to the virus decreases over time, the virus travels down the nerve cells and causes a painful rash. Usually occurs in adults about the age of 50 years, although can occur at any age.

Hib


Haemophilus influenzae type b; a bacterium that causes meningitis and other serious infections in young children.

HIV


Human immunodeficiency virus, which can over time develop into AIDS (Acquired Immune Deficiency Syndrome). People with HIV infection have weakened immunity and have special vaccination requirements.

Human papillomavirus (HPV)


Human papillomavirus (HPV) is a highly contagious virus that affects both males and females and can cause HPV-related cancers and disease, including cervical, anal, penile, throat cancers and genital warts. HPV is spread by direct, skin-to-skin contact during all types of sexual activity with a person who has the virus.

Hypotonic-hyporesponsive episode (HHE)


A rare event which may follow some hours after DTPa (diphtheria, tetanus, pertussis) vaccination. The child becomes pale, limp and unresponsive and the condition may last from a few minutes to hours but causes no long-term serious problems.

Immunisation


The process of bringing about immunity to a particular infective agent (such as a bacterium or virus) by giving a vaccine. The terms vaccination and immunisation are not exactly the same; vaccination is the process of giving a vaccine, while immunisation is the process of both giving a vaccine and the body developing an immune response as a result of the vaccine.

Immunity


The ability of the body to fight off certain infections. Immunity can result from natural infection or from vaccination.

Immunogenicity


The ability of a vaccine to bring about an immune response.

Immunoglobulin


A protein extract from blood, sometimes called ‘antibody’, which fights off infection; injection of immunoglobulins provides temporary immunity against certain infections.

Incubation period


After a person is infected with bacteria or viruses, it often takes days or weeks for the infection to cause symptoms and an obvious illness. The time between infection and the start of symptoms is called the incubation period.

Infection


An infection occurs when bacteria or viruses invade the body. If the body cannot fight the infection, it may cause an illness.

Intradermal injection


An injection into the surface layers of the skin (dermal means skin).

Intramuscular (IM) injection


An injection into the muscle. Vaccines are usually injected into a muscle of the upper outer thigh, or a muscle in the upper arm.

IPV


Inactivated poliomyelitis vaccine. An injectable vaccine that protects against polio.

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J K L



JE


Japanese encephalitis - a brain infection caused by the Japanse encephalitis virus.

Jaundice


Yellow skin colour that may happen when a person has severe hepatitis.

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M N O



Meningococcal infection


An infection caused by the bacterium Neisseria meningitidis which can result in meningitis (inflammation of the membranes around the brain and spinal cord) and other serious infections. The bacterium is also known as meningococcus.

Micro-organisms


Small living organisms that can only be seen with a microscope.

MMR


The measles-mumps-rubella vaccine.

OPV


Oral (taken by mouth) poliomyelitis vaccine - also known as Sabin vaccine. This vaccine is no longer available in Australia.

Outbreak


An outbreak is an epidemic that is limited to a localised increase in the incidence of a disease, for example, to a town or institution.

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P Q R S



Pandemic, pandemic influenza


A pandemic epidemic occurs over a very wide area, crossing international boundaries and usually affects a large number of people. For example, pandemic influenza is when there is a global epidemic of influenza that results when a new strain of influenza (flu) virus appears in the human population. It may cause more severe disease in the population due to little immunity to the new strain.

Paracetamol


A medicine that helps to reduce fever; it may be given to minimise fever following vaccination.

Pertussis


Whooping cough, an illness caused by a bacterium, Bordetella pertussis.

Pneumococcal infection


An infection caused by a bacterium Streptococcus pneumoniae which can result in pneumonia (lung infection) and other serious infections. The bacterium is also known as pneumococcus.

Polysaccharide


A group of complex carbohydrates (sugars) which make up the cell coating of some bacteria.

PRP-OMP


A type of Hib vaccine, where the Hib sugar is conjugated to a meningococcal protein (see Conjugation). It produces an early antibody response.

PRP-T


A type of Hib vaccine, where the Hib sugar is conjugated to a tetanus protein (see Conjugation).

Rotavirus


A virus that can cause severe diarrhoea and vomiting, especially in children.

Rubella


A viral illness, also known as German measles.

Shingles (herpes zoster infection)


This illness is caused by reactivation of the varicella-zoster virus, the virus that causes varicella (chickenpox). The virus remains in the nerve cells for a long time after recovery from varicella. As immunity to the virus decreases over time, the virus travels down the nerve cells and causes a painful rash. Usually occurs in adults about the age of 50 years, although can occur at any age.

Single-disease vaccine


A vaccine designed to immunise against a single disease. It may contain several components to protect against different strains or types of the same micro-organism that cause the disease (e.g. influenza vaccine).

Subcutaneous (SC) injection


An injection into the tissue between the skin and the muscle underneath.

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T U V



Triple Antigen


Another name for the diphtheria-tetanus-pertussis vaccine (for children).

Vaccination


The administration of a vaccine. [The terms vaccination and immunisation are not exactly the same; vaccination is the process of giving a vaccine, while immunisation is the process of both giving a vaccine and the body developing an immune response as a result of the vaccine.]

Vaccine


A product made from whole, or extracts of, killed viruses or bacteria, or from live weakened strains of viruses or bacteria.

Varicella


Varicella (chickenpox) is an infection caused by the varicella-zoster virus, which belongs to the herpes group of viruses.

VZV


Varicella-zoster-virus, which causes Varicella (chickenpox) and zoster (shingles)

Virulence


How well or quickly a virus or bacteria is able to cause disease in a person.

Virus


A tiny living organism, smaller than a bacterium, that can cause infections. Examples of infections caused by virus include measles, rubella, mumps, polio, influenza (flu) and hepatitis B.
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W X Y Z



Zoster


An abbreviation for herpes zoster infection (shingles), which is a painful rash and illness caused by the reactivation of the varicella-zoster virus (chickenpox).

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Page last modified: 05 May, 2009