Adverse Events Following Immunisation

Page last updated: 20 April 2015

Serious reactions to immunisation are very rare. It is not unusual however for those receiving vaccines to experience some discomfort or to have minor side effects, such as pain, swelling or redness at the injection site. Most of these reactions are mild in nature and are quickly resolved.

If you or someone in your care is experiencing an adverse event or think you may be experiencing one, please seek advice from a health professional. If you need urgent medical help call 000. The adverse event should then be reported to the Therapeutic Goods Administration or your relevant state or territory health authority.

What is an adverse event?

An adverse event following immunisation (AEFI) is any unwanted medical reaction in a person who has been administered a vaccine. Adverse events may refer to any unfavourable or unexpected laboratory finding, symptom or disease that follows vaccination. The vaccine does not necessarily have to have caused the adverse event.

Managing adverse events

The most serious immediate AEFI is a severe allergic reaction known as anaphylaxis. Severe anaphylactic reactions usually have a rapid onset. Severe anaphylactic reactions to vaccines are very rare. However this is why people receiving vaccinations are usually requested to remain in the vicinity of the place of vaccination for at least 15 minutes.

In adults and older children, the most common immediate adverse event is a fainting episode. Because fainting after vaccination can lead to serious consequences, anyone who complains of giddiness or light-headedness before or after vaccination should lie down until free of symptoms. Most faints following vaccination occur within five minutes, and 98% occur within 30 minutes. This is why you are often warned not to drive or operate machinery for at least 30 minutes after vaccination.

Managing vaccine discomfort

Vaccine injections may result in soreness, redness, itching, swelling or burning at the injection site for one to two days. Placing a clean, cold, wet cloth over the injection site will often relieve discomfort or sometimes Paracetamol may be given to ease discomfort. Occasionally a small, hard lump may persist for some weeks or even months. This should not be of concern and requires no treatment.

Managing fever

If you or your child develops a fever after vaccination, drink extra fluids and do not overdress an infant if they become hot. Paracetamol may be given if an infant or child develops a high fever. The dose of paracetamol is 15 mg/kg of paracetamol liquid, up to a maximum daily dose of 90 mg/kg per day.

Children who have had a serious AEFI

Children who have had a serious AEFI (other than one which is a contraindication to further vaccination, such as anaphylaxis) may be subsequently vaccinated under close medical supervision. Most states and territories offer an adverse event immunisation clinic where parents or carers can get advice regarding revaccination and receive supervised vaccinations if required; where there is no such clinic, there is often a paediatrician or infectious diseases specialist who will assist families with vaccination concerns. For more information about adverse event services, contact your state or territory health department.

Importance of reporting an adverse event

Reporting an AEFI is important to assist the Therapeutic Goods Administration (TGA) to monitor issues of vaccine safety and to address any risks which may be identified. Further information can be found at the TGA Safety Information web page.

How to report an adverse event

Adverse events should be reported to your relevant state or territory health authority, or directly to the TGA. Notifications received by health authorities are referred to the TGA, which manages the Australian Adverse Drug Reactions System (ADRS) for adverse reaction reports. Information on how to report an AEFI is available at the TGA Safety Information page. State and territory contacts for reporting adverse events are as follows:

  • ACT - ACT Health Department - 026205 2300
  • NSW - 1300 066 055 (To connect to your local Public Health Unit)
  • NT - NT Department of Health - 08 8922 8044
  • QLD - Queensland Health - 07 3328 9888 or complete an AEFI initial report form available at Queensland Government - Immunisation website
  • SA - Immunisation Section, Department of Health - 1300 232 272
  • TAS - Direct to TGA - 1800 044 114
  • VIC - SAEFVIC - 1300 882 924 or SAEFVIC
  • WA - State Health Department - WAVSSS - 08 9321 1312.

Consumers and immunisation providers in any jurisdiction can report directly to the TGA using the 'blue card' reporting form or by phoning 1800 044 114

For more information about adverse events, please refer to the AEFI page for health professionals on this website.

What happens when an AEFI is received by the TGA?

Each report of an adverse event following a vaccine received by the TGA is entered into the Australian Adverse Drug Reactions System (ADRS). The information in the ADRS is analysed by TGA staff to identify any safety signal - a flag for a possible safety concern. If the TGA identifies a signal against a reported adverse event, it undertakes an assessment to establish whether the vaccine was in any way responsible and where required takes appropriate actions to manage the risks.

Three months after an adverse event report is first entered in ADRS, the checked and analysed information is transferred to the publically accessible Database of Adverse Event Notifications (DAEN).