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Health professionals

Find information that will help you deliver your service to your patients

Are vaccines safe?

Health professionals

Find information that will help you deliver your service to your patients

Vaccine testing

Research and testing is an essential part of developing safe and effective vaccines.

In Australia, every vaccine must pass strict safety testing before the Therapeutic Goods Administration (TGA) will register it for use. Approval of vaccines can take up to 10 years.

Before vaccines become available to the public, they are tested on thousands of people who take part in large clinical trials.

    A fact sheet about how vaccines are shown to be safe, noting how all vaccines are carefully tested.

    Vaccine ingredients

    Vaccine ingredients vary depending on what the vaccine is used for. 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.

    Fact sheet about vaccine ingredients, noting that all ingredients are tested for safety.

    You can also search the TGA's product information for more detail about each vaccine and its specific ingredients.

    Vaccine side effects

    You may experience minor side effects following vaccination. Most side effects last no more than a couple of days and you will recover without any problems.

    Common reactions to vaccination include:

    • pain, redness and/or swelling where you received the needle
    • mild fever.

    Serious reactions like allergic reactions are extremely rare. If you have a reaction that you think is severe or unexpected, seek medical advice straight away. 

    If you have any concerns about potential side effects of vaccines, talk to your doctor or nurse.

    Vaccine safety monitoring

    The TGA and the company that makes the vaccine closely monitor how well a vaccine is working and how safe it is in the community.  

    Vaccines are monitored and tested after their introduction in a number of ways, including:

    • further clinical trials
    • national surveillance
    • monitoring of serious side effects.

    In Australia, immunisation experts actively monitor vaccine safety. They do this by following up vaccinated children and adults and asking if they have had a reaction. This data is made publicly available.

    You can report adverse events directly to the TGA online using:

    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 (ACV). This ensures there is ongoing safety assessment of vaccines.

    If you would like to report a side effect to a vaccine by telephone, you are encouraged to speak to a pharmacist from NPS MedicineWise  on 1300 134 237. The pharmacist can both lodge the report and provide further advice on how to manage the side effect. 

    You can also report AEFIs to your state or territory health service.

    Mercury is no longer used in vaccines

    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.

    No established link between vaccines and autism

    High quality studies over many years have compared the health of large numbers of vaccinated and unvaccinated children. 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 The Lancet in 1998, claiming a link between the measles, mumps, rubella vaccine and autism. The paper has since been completely discredited and was withdrawn from the Lancet in 2010. The journal printed an apology after withdrawing the paper.

      This fact sheet explains how we know vaccination does not cause autism and where the misunderstanding came from.

      Further information

      You can find more information on vaccine safety in the following resources:

      This booklet helps health professionals respond to arguments against vaccination.

      Last updated: 
      1 August 2018