Anaphylaxis following vaccination is a rare but serious adverse event that can be fatal.
Anaphylactic reactions following vaccination are rare and are caused by the vaccine antigen itself or more commonly an ingredient found in the vaccine.
A pre-vaccination screening questionnaire must be used to screen people for contraindications to the vaccine and prevent anaphylactic reactions.
Severe anaphylactic reactions usually occur, within 15 minutes of vaccination. Observe all individuals for at least 15 minutes after vaccination to monitor for immediate reactions.
Anaphylaxis is characterised by sudden respiratory compromise and/or circulatory collapse and can be difficult to distinguish from a vasovagal episode (fainting) which is more common. Refer to the following table of clinical features that may help differentiate between the two.
Respiratory symptoms or signs
Cardiovascular symptoms or signs
Skin symptoms or signs
Gastrointestinal symptoms or signs
Neurologic symptoms or signs
Australian Immunisation Handbook - Clinical features that may help differentiate between a vasovagal episode and anaphylaxis
Vaccination clinics must have an anaphylaxis response kit to manage anaphylaxis, refer to the Australian Immunisation Handbook.
If a person presents with signs and symptoms of anaphylaxis:
13 years & over
0.50 ml (max dose)
Management of anaphylaxis in pregnant women is the same as for non-pregnant women. However, pregnant women should be positioned on their left side to maintain adequate cardiac output.
All patients treated for anaphylaxis must be transferred to a hospital for observation for at least 4 hours after the last dose of adrenaline due to the risk of relapse or protracted reactions.
Anaphylaxis can be fatal if not managed appropriately, the greatest risk factors include: