Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
1
Is any of this happening now?
Call 911
Call emergency services immediately for possible severe allergy, including:
Trouble breathing or noisy breathing
Swelling of the face, lips, tongue, or throat
Widespread hives with dizziness, weakness, or collapse
Sudden confusion or loss of consciousness
Other emergency signs, for anyone
Someone who is struggling to breathe, gasping, choking, or cannot get words out
Someone who has chest pain, tightness or pressure lasting more than a few minutes
Someone who has sudden weakness or drooping on one side of the face or body, slurred speech, or sudden confusion
Someone who is unconscious, or cannot be woken
Someone who is bleeding heavily and it will not stop with firm pressure
Someone who has had a seizure that will not stop, or does not wake up afterwards
Someone who has lips or skin that look pale, blue, grey or blotchy
Someone who you believe has taken an overdose or swallowed something poisonous
2
Is any of this happening?
Be seen today
Seek urgent medical advice if you have signs of a serious vaccine-specific complication described in the information you were given.
Do not wait for routine follow-up if these symptoms occur.
3
Does any of this apply?
Book an appointment
Contact your healthcare team for routine advice if side effects are worsening, are not settling as expected, or are interfering with eating, drinking, sleep, or normal activity.
Also call if you develop an unexpected rash, significant swelling, persistent fever, or symptoms that concern you.
Every sign above is quoted from the sofidex article on Immunizations. If you are not sure, err upward — it is always reasonable to be checked.