Immunisation

Immunisation refers to receiving a vaccine and becoming immune to a particular disease as a result of being vaccinated against that disease.

Vaccination refers to receiving a vaccine. Vaccines can be given either by an injection as in the case of the MMR vaccine or via the mouth, such as the Rotavirus vaccine.

>> Links

National Centre for Immunisation Research and Surveillance

Health Department of Western Australia

Australian Government Department of Health and Ageing

When someone is vaccinated, their body produces an immune reponse in the same way their body would if they were exposed to a disease, however they do not suffer any symptoms of the disease. An immune response occurs when the immune system attacks organisms and substances that invade our body and cause disease. If the person comes in contact with the disease in the future, their immune system would respond so that they did not develop the disease.

Vaccines can contain either a very small dose of a live, but weakend form of a virus; killed bacteria or virus or small parts of bacteria; or modified toxin produced by bacteria. So the vaccines will remain effective for a long time they can also contain small amounts of preservative or antibiotic. To help produce a better immune response, some vaccines may also contain a small ammount of aluminium salt.

Generally, it takes about two weeks for immunisation to provide protection from an infection. To ensure protection against a disease lasts a long time, most vaccines need to be given several times. For example, for someone who has only received one or two doses of the DTPa-IPV (diptheria-tetanus-whooping cough(pertussis)-polio) they will only be partially protected and may become ill if exposed to any of these diseases.

Immunisations do not always provide protection for a persons lifetime, therefore booster doses may need to be given. Tetanus vaccines can last up to 30 years, however other vaccines such as whooping cough give protection for only about five years. Not everyone is protected against the disease, even when all doses of a vaccine have been given. If enough people are immunised then the infection cannot be spread from person to person and therefore the disease will die out altogether. This is how smallpox was eliminated from the world as well as polio in many countries.

Compared with other Australian states and territories, Western Australia has the lowest child immunisation coverage.