Are vaccines safe?
Research and testing for safety is an essential part of developing vaccines.
In Australia, every vaccine must pass strict safety testing before the Therapeutic Goods Administration (TGA) will register it for use.
All vaccines are tested for safety in multiple stages of clinical trials. The National Immunisation Program has further details about what these vaccine clinical trials involve within the how are vaccines shown to be safe fact sheet.
The TGA also monitors and assesses vaccines to ensure they are safe and effective once they are in use in Australia.
Vaccines are monitored and tested after their introduction in a number of ways, including:
- further clinical trials
- national surveillance
- monitoring of serious side-effects
You can report adverse vaccine events directly to the TGA. The TGA reviews these reports on a regular basis. The TGA can refer the reports as required to expert committees, such as the Advisory Committee on Vaccines. This ensures there is ongoing safety assessment of vaccines.
In Australia, immunisation experts actively monitor vaccine safety by following up vaccinated children and adults and asking if they have had a reaction. The data from this follow up is then published.
Some children may experience minor side effects following immunisation. Most side effects last a short time and the child recovers without any problems.
Common reactions to immunisation include:
- pain, redness and/or swelling at the injection site
- mild fever.
Serious reactions such as allergic reactions are extremely rare. If a reaction occurs that you consider severe or unexpected, seek medical advice straight away.
If you have any concerns about side effects of vaccines, talk to your doctor or nurse.
Wide and varied studies show no increase in allergy or asthma due to childhood vaccines.
Vaccination helps children with asthma or allergic disease. It helps them by reducing their likelihood of getting a serious infection, that could make their asthma or allergy symptoms worse.
If you’re concerned about your child’s allergies or asthma in relation to vaccination, speak to your doctor or immunisation provider.
Vaccine ingredients vary according to the serious diseases they prevent or minimise. They may contain:
- a very small dose of a live (but weakened) virus
- killed viruses
- killed bacteria
- small parts of bacteria
- a small dose of a modified toxin produced by bacteria
- a small amount of preservative
- a small amount of an antibiotic to preserve the vaccine
The National Immunisation Program website provides further details about the ingredients in vaccines in the what is in vaccines factsheet.
You can also search the TGA's product information for more details about vaccines and their specific ingredients.
Thiomersal which contains mercury was used as a preservative in some vaccines in very small amounts.
Thiomersal was removed from all vaccines on Australia’s National Immunisation Program in 2000.
There is no scientific evidence the small amounts of the thiomersal used in vaccines caused any harmful effects in children or adults.
Many large studies have found no link between vaccines and autism.
A number of high quality studies compared the health of large numbers of vaccinated and unvaccinated children over many years. Medical information from nearly 1.5 million children living around the world was able to confirm that vaccination does not cause autism.
The concern around autism and immunisation came from a paper published in 1998 claiming a link between the MMR (measles, mumps, rubella) vaccine and autism. The paper was withdrawn from the journal in 2010 after the General Medical Council found that results reported in the paper had "proven to be false". The journal printed an apology after withdrawing the paper.
The National Immunisation Program website provides further information about vaccines and autism in the What about autism? fact sheet.
Page last updated: 06 Sep 2017