22 Jan Immunisation Fact Sheet
Immunisation is a simple, safe and effective way of protecting people against harmful diseases before they come into contact with them. Immunisation not only protects individuals, but also the community, by reducing the spread of preventable diseases.
You may have heard the terms immunisation and vaccination and wondered what the difference is.
- Vaccination is when a vaccine is administered to you (usually by injection)
- Immunisation is what happens in your body after you have the vaccination. The vaccine stimulates your immune system so that it can recognise the disease and protect you from future infection (i.e. you become immune to the infection).
Many immunisations are available free of charge in Australia through the National Immunisation Program.
How your immune system works
Every day you come into contact with germs, including bacteria and viruses. A healthy immune system stops you from getting sick from these germs. The immune system is our 24/7 bodyguard that’s at work all the time to keep us as healthy as possible. It recognises harmful bacteria, viruses and any other substances, also known as antigens, when they enter your body.
When an antigen like the cold virus enters your body, your immune response first produces something called mucus. The mucus tries to flush out the virus and stop more of it from entering the body. Next, your immune response can send white blood cells to surround the virus to prevent more harm. Lastly, it can produce special proteins called antibodies. Antibodies can lock onto and destroy the virus.
Vaccines strengthen your immune system
Vaccines strengthen your immune system by training it to recognise and fight against specific germs. They are a safe and clever way of producing an immune response in the body without causing illness.
Vaccines use dead or severely weakened viruses to trick our bodies into thinking we have already had the disease. When you get a vaccine, your immune system responds to these weakened ‘invaders’ and creates antibodies to protect you against future infection. It has special ‘memory’ cells that remember and recognise specific germs or viruses.
When you encounter that virus in the future, your immune system rapidly produces antibodies to destroy it. In some cases, you may still get a less serious form of the illness, but you are protected from the most dangerous effects.
Vaccination doesn’t merely protect you. It helps protect the health of future generations, as it has with the crippling disease polio.
Is ‘natural’ immunisation better?
If a disease infects you, then you may become immune to it in the future. This is known as ‘natural’ immunity.
Some people believe that natural immunity is better than the immunity from vaccines. But the risks associated with natural immunity are much higher than risks associated with immunity provided by vaccines. Some highly contagious diseases can lead to severe complications. They can make you very ill or even kill you.
The benefits of vaccination far outweigh the risks. Vaccination protects you and your family from diseases, including ones that are deadly. It also protects other people in your community, including people who are vulnerable, too young, or too sick to be immunised.
Immunisation for children
If fully immunised, your child is far less likely to catch a particular infection or if they do, their symptoms will tend to be much less severe. Vaccination also provides herd immunity, meaning if enough people are immunised against a bacteria or virus, the infection will not be able to spread easily from person to person.
Routine vaccinations start shortly after birth, with an injection for hepatitis B. At six to eight weeks, there is a combined injection for diphtheria, tetanus, whooping cough, hepatitis B, poliomyelitis and haemophilus influenzae type b (Hib) as well as another for pneumococcus, and oral drops for rotavirus. This is repeated again at four and six months. Other combined injections follow, and because immunity may weaken over time, booster doses of some vaccines will be required throughout your lifetime.
Immunisation for adolescents
It is recommended that teenagers receive additional immunisation against diphtheria, tetanus, whooping cough, human papillomavirus (HPV), and meningococcal disease (strains A, C, W and Y). Two boosters are recommended in the teenage years.
- At 12-13 years of age a booster against diphtheria, tetanus and whooping cough. This is given as a single injected dose of a three-in-one vaccine.
- At 14-16 years a booster against the A, C, W and Y strains of meningococcal disease, given as a single injected dose.
Remember that new vaccines have been introduced in recent years and that some teenagers may have missed immunisations in childhood. It is wise to check with your doctor to find out whether catch-up immunisations are advisable.
Immunisation for adults
Vaccination for adults aged from 20 to 64 and beyond is just as important as it is for children. The kind of vaccines you need will depend on several factors, including:
- whether you missed out on childhood vaccines
- if you are Aboriginal and/or Torres Strait Islander
- your job
- how old you are
- whether you plan on travelling.
Speak to your doctor or vaccination provider about your or your family’s specific needs, including catch-up vaccinations where vaccines may not have been available or if you are not sure whether you received them.
In addition, the Australian Government recommends the following vaccines for adults:
- Shingles (herpes zoster) – for all adults aged 60 years or more
- Influenza – recommended for everyone aged six months or more.
Risks and complications
The risk of not immunising outweighs the risks of vaccination. It is common for some redness and swelling to appear around the injection site or for a child to display a mild fever. Occasionally, a severe allergic reaction called anaphylaxis may occur, but this is extremely rare, arising in about one in every million vaccine doses.