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What about side-effects?

Key facts

  • Some babies and children feel a little unwell or unsettled for a day or two after vaccination, and then get better, with just a little bit of love and care from you at home.

  • Serious side effects are very rare. When they do occur, it is important for babies and children to get the support they need from healthcare professionals or at a hospital.

Last updated on 16 June 2023.
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Will my child have a reaction to the vaccines?

Some babies and children could feel a little unwell or unsettled for a day or two after they get their vaccinations. Most of the common reactions will last between 12 and 24 hours and then get better, with just a little bit of love and care from you at home.

Can the vaccines have any serious side effects, even if they are rare?

Serious side effects are very rare, but they can happen and some parents want to know more about them before they vaccinate their children.

Around one in every 3,000 babies experiences fits or seizures known as ‘febrile convulsions’ after vaccination. Febrile convulsions are scary for parents to see, but babies usually recover quickly without any long-term effects.1 Febrile convulsions can occur when a baby’s temperature goes up very quickly, and stop once their temperature stops rising.

‘Anaphylaxis’ is a severe allergic reaction to one of the vaccine ingredients. Less than one in every one million children has this reaction.1 Anaphylaxis usually happens within a few minutes of vaccination, before you and your baby or child leave the clinic, and can be treated with an injection of adrenalin. People who have this reaction usually recover quickly and don’t experience any long-term effects.

Around 59 babies in every one million who get the rotavirus vaccine experience a blockage of the intestine called an ‘intussusception’.1 The blockage gives babies strong bouts of pain in their tummies which can make them look pale, weak and very sick. They may vomit. Babies who have signs of intussusception need to go to hospital quickly so they can get the help they need. Babies who are treated for intussusception usually don’t have any long-term health problems.

Around three to five children among every one million children who get the MMR vaccine to protect them against measles, mumps and rubella have a reaction that causes a condition called thrombocytopenia (a low platelet count in the blood).1 Thrombocytopenia causes children to bruise or bleed very easily. It usually lasts for between one and six months and then gets better. These side effects are less common after the MMRV vaccine is given at 18 months, because it is the second dose of a vaccine that contains MMR.

Guillain-Barré syndrome is a rare disorder where the immune system damages nerve cells. It usually begins with tingling and weakness in the feet or legs and can lead to temporary paralysis. Less than one out of every one million people who get an influenza vaccine get Guillain-Barré syndrome. Children don’t get the disorder as often as older adults. People infected with influenza are more likely to get Guillain-Barré syndrome than people who get the influenza vaccine.2

  1. Australian Technical Advisory Group on Immunisation (ATAGI). Australian Immunisation Handbook, Australian Government Department of Health, Canberra, 2018,
  2. National Centre for Immunisation Research & Surveillance. Influenza vaccines - Frequently Asked Questions. National Centre for Immunisation Research & Surveillance: Sydney, Australia. Available at: