Adjuvant
A vaccine component distinct from the antigen that enhances the immune response to the antigen.
Adverse event
An unexpected, unwanted, or serious reaction to a medication or vaccine.
Adverse event following immunisation
Any untoward medical occurrence that follows immunisation. It does not necessarily have a causal relationship with the vaccine
Advisory Committee on Vaccines (ACV)
The ACV provides independent medical and scientific advice to the Australian Government’s Minister for Health and the Therapeutic Goods Administration (TGA) on issues relating to the safety, quality and efficacy of vaccines supplied in Australia including issues relating to pre-market assessment, post-market monitoring and safe use in national immunisation programs.
Anaphylaxis
An immediate and severe allergic reaction to a substance (e.g. food or drugs). Symptoms of anaphylaxis include breathing difficulties, loss of consciousness and a drop in blood pressure. This condition can be fatal and requires immediate medical attention.
Antigen
A foreign substance which is detected by the immune system. The presence of antigens in the body triggers an immune response, usually the production of antibodies.
Association
The degree to which the occurrence of two variables or events is linked. Association describes a situation where the likelihood of one event occurring depends on the presence of another event or variable. However, an association between two variables does not necessarily imply a cause-and-effect relationship. The term association and relationship are often used interchangeably
Asymptomatic
A person that is not showing symptoms
Attenuated vaccine
An attenuated vaccine (or a live attenuated vaccine) is a vaccine created by reducing the virulence of a pathogen but keeping it viable (or "live"). Attenuation takes an infectious agent and alters it so that it becomes harmless or less dangerous. These vaccines contrast to those produced by "killing" the virus (inactivated vaccine).
Australian Immunisation Register
It is a national register that records all vaccines given to all people in Australia