Immunisation side effects
If you think someone is having a severe allergic reaction after a vaccination, call triple zero (000) and ask for an ambulance.
Key facts
- Immunisation side effects are unwanted effects that may happen after you get a vaccine.
- Common vaccine side effects are usually mild and go away quickly.
- See your doctor as soon as possible if you are worried about yourself or your child after getting a vaccine.
- After getting a vaccine, you will need to wait at the clinic for 15 minutes to check for side effects.
- Immunisation side effects can’t be prevented.
What are immunisation side effects?
Immunisations are a safe and effective way to prevent some diseases. However, like all medicines, vaccines can cause unwanted side effects.
Common immunisation side effects are usually mild and go away quickly. They usually happen in the first few days after your vaccination.
A serious reaction after vaccination is rare. For most people, the chance of having a serious vaccine side effect is much lower than the chance of becoming very ill from the disease.
Vaccine side effects are sometimes called adverse effects or adverse events.
Talk with your doctor or nurse if you have any concerns about vaccine side effects.
Find out more about the difference between immunisation and vaccination.
What symptoms are related to immunisation side effects?
Most vaccine side effects happen at the injection site (where you got the needle), such as:
- pain
- redness
- itching
- swelling or burning
You may also get a mild fever and feel tired.
These immunisation side effects are expected and are generally mild. These symptoms usually last for 1 to 2 days.
There is a very small chance of a serious side effect after any vaccine.
Serious adverse effects that may happen after immunisation are:
- anaphylaxis — very rare, but can be fatal (cause death)
- intussusception — a type of bowel obstruction
- seizure
- rash
Anaphylaxis usually happens within 15 minutes of vaccination.
Early signs of anaphylaxis are:
- hives — skin rash
- red, itchy skin
- difficulty breathing
- cough
- hoarse voice
CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.
What causes immunisation side effects?
Symptoms that you get after immunisation could be:
- due to the vaccine
- a coincidence — they would have happened anyway
How is the cause of immunisation side effects diagnosed?
You will need to wait for at least 15 minutes at the clinic after getting a vaccination. This is to check for any immediate side effects and ensure medical treatment can be given rapidly. Most serious side effects usually start within 10 minutes of vaccination.
If you do have a serious side effect, your immunisation provider will give you medical care and get advice from:
- a specialist immunisation clinic
- your state or territory health authority
This advice is important to:
- work out if there is a link between the side effect and vaccine
- consider the benefits and risks of you having further vaccinations
- plan how you should get extra doses of that vaccine or other vaccines
Your immunisation provider could be a:
ASK YOUR DOCTOR — Preparing for an appointment? Use the Question Builder for general tips on what to ask your GP or specialist.
How are vaccine side effects reported in Australia?
It’s important to report vaccine side effects. This gives government health officials a better understanding of vaccine safety.
You can report vaccine reactions to your state or territory health service. Or you can report a vaccine side effect to the Therapeutic Goods Administration.
When should I see my doctor?
See your doctor as soon as possible if you are worried about yourself or your child after getting a vaccine.
When to seek urgent care
If you think someone is having a severe allergic reaction after a vaccination, call triple zero (000) and ask for an ambulance.
Go to the emergency department of a hospital if:
- your baby has sudden unusual screaming events with vomiting
- your baby has blood in their bowel motion (poo)
- you have a reaction to a vaccine that you consider serious or unexpected
Serious reactions to vaccines are rare. Anaphylaxis is the most serious form of allergic reaction and can be life threatening.
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How are immunisation side effects treated?
You usually don’t need treatment for mild immunisation side effects.
Self-care at home
You can manage mild vaccine side effects by:
- drinking more fluids
- resting
- taking paracetamol
- removing layers of clothes if hot
It helps to keep your arm moving after an immunisation.
If your injection site is red and warm to touch, put a cool wet cloth on your arm. Do not use an ice pack.
Self-care at home for your baby or young child
If your baby or young child is unsettled after a vaccine, you might need to comfort them by:
- cuddling them more often
- offering more feeds during the day
- giving them a bath
If your baby feels hot, do not put them in lots of clothes or blankets.
If their injection site is red and warm to touch, put a cool wet cloth on their leg or arm. Do not use an ice pack.
If your baby has a fever (temperature of 38°C or higher), you can give them paracetamol or ibuprofen. Always follow the directions on the bottle.
Find out more about immunisation and vaccinations for your child.
Medicines for immunisation side effects
You can take paracetamol or ibuprofen if you have:
- a fever of 38°C or higher after vaccination
- pain at the injection site
Generally, it’s not advised to take paracetamol or ibuprofen before or straight after a vaccination. However, you can give paracetamol to infants under 2 years of age who are getting the MenB vaccine (meningococcal B).
Other treatment options
If you or your child have an anaphylactic reaction to a vaccine, you will be treated with adrenaline.
This is usually given through an adrenaline autoinjector (EpiPen). Autoinjectors give a single dose of adrenaline.
If you think someone is having a severe allergic reaction after a vaccination, call triple zero (000) and ask for an ambulance.
What are the complications of immunisation side effects?
If you have a serious side effect to a vaccine, it will affect how you get vaccines in the future.
Most people can still get vaccinated, but you will be watched closely.
Diseases or conditions that are unrelated to vaccines
Research has shown that there is no link between these vaccines and conditions:
- any vaccine — asthma or sudden infant death syndrome (SIDS)
- MMR vaccine — autism or inflammatory bowel disease
- hepatitis B vaccine — multiple sclerosis (MS)
- Hib vaccine — diabetes
Can immunisation side effects be prevented?
You cannot prevent immunisation side effects. However, your immunisation provider should talk with you about common side effects and how to deal with them.
This should be done before you consent to you or your child getting a vaccine.
You will be told to stay at the clinic for a short time after your vaccination for monitoring.
Resources and support
- To learn more about vaccine side effects, talk with your immunisation provider.
- Find out more about common side effects from vaccines in the National Immunisation Program.
- Read more about what to expect and what to do after vaccination.
- The Consumer Medicine Information (CMI) also lists the side effects of each vaccine. These are on the Therapeutic Goods Administration website.
- Learn how to read Consumer Medicine Information (CMI).
- You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with you 24 hours a day, 7 days a week.
Learn more here about the development and quality assurance of healthdirect content.
Last reviewed: May 2025
