Vaccine contraindications, precautions and adverse events — formative SAQs

SAQ 1 — Screen and decide (10 marks)

A 2-month-old is due for primary immunisations. Mother reports a mild cold, temperature 37.7°C, and says an older cousin “reacted badly” to vaccines and later received an autism diagnosis. The infant is feeding well and looks well. [1] [4]

Questions

1. Define contraindication, precaution and false contraindication, and classify each of the mother’s concerns. (4 marks) [1]
2. List the essential pre-vaccination safety screen items you still complete. (3 marks) [1] [3]
3. State your decision for today and the counselling points you document. (3 marks) [1] [4]

Model answer

Definitions and classification (4). Contraindication: condition that markedly increases serious adverse-reaction risk — withhold that vaccine. Precaution: condition that may increase risk, impair response or confuse later assessment — usually defer. False contraindication: believed barrier without safety justification — vaccinate. Mild cold/low-grade fever in a well infant is a false contraindication (or at most not a reason to cancel). Family autism history is a false contraindication. No true contraindication is described. [1] [4]

Safety screen (3). Identity and vaccines due; prior anaphylaxis to dose/component; severe immunocompromise or suspected IEI before live products; pregnancy only if relevant; recent antibody products before live vaccines; current illness severity; observation/adrenaline readiness. [1] [3]

Decision and counselling (3). Vaccinate today if the screen is clear. Explain expected common reactions, when to seek urgent care, and that autism family history is not a vaccine safety stop. Document consent discussion and rebooking if any temporary issue appears. [1] [4]

SAQ 2 — Anaphylaxis and special populations (10 marks)

A. An 8-week-old develops multi-system features of anaphylaxis 10 minutes after combination primary vaccines. B. Separately, a well sibling of a child with SCID attends for scheduled vaccines including live products where used in the programme. [2] [3] [8]

Questions

1. Outline immediate management of vaccine anaphylaxis and the immunisation record action that follows. (4 marks) [2] [7]
2. Explain live-vaccine principles for the SCID index child versus the healthy sibling contact. (3 marks) [3] [8]
3. Give one rare non-anaphylaxis serious AEFI candidates must name, with the practical clinical priority. (3 marks) [5] [6]

Model answer

Anaphylaxis (4). Call for help; IM adrenaline into anterolateral thigh without delaying for antihistamines; airway/oxygen; fluids if shocked; repeat adrenaline if needed; observe/admit as indicated; document lot/timing; report serious AEFI; record permanent contraindication to the culprit vaccine/component and plan specialist review for future antigens. [2] [7]

SCID household (3). Index child with SCID: no rotavirus, no BCG, and broader live-vaccine avoidance until immunology directs otherwise. Healthy sibling: generally still vaccinate on schedule to protect the household; avoid OPV-type products that can transmit where those are used; MMR/varicella vaccine viruses are not a reason to leave the sibling unvaccinated. [3] [8]

Other serious AEFI (3). Examples: intussusception after rotavirus — treat as surgical emergency first; or ITP after MMR — check platelets/haematology pathway, rare and usually self-limited, antigen-specific future plan. Do not use passive reports alone as proof of causation. [5] [6] [7]