skip to main content

Measles post-exposure prophylaxis — MCCQE Part 1 MCQ

Instant feedback + full explanation. One question, done properly.

ModerateVaccinationMeasles post-exposure prophylaxisMCCQE Part 1

10-month-old infant presents with exposed to measles in a clinic waiting room. The infant is too young for routine MMR and exposure was 2 days ago. Which of the following is the most appropriate next step?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: C — Contact public health and provide MMR or immunoglobulin depending on age, timing and risk category

Contact public health and provide MMR or immunoglobulin depending on age, timing and risk category is best because measles exposure management depends on age, susceptibility and timing. Use a United States screening schedule instead of Canadian guidance is suboptimal because MCCQE questions expect Canadian preventive-care guidance; Defer all preventive care until symptoms develop is suboptimal because screening and immunisation aim to prevent disease before symptoms; Order the most invasive test as routine first-line screening is suboptimal because screening should balance benefit, harm and resource use; Screen at every visit regardless of interval or prior results is suboptimal because over-screening causes avoidable false positives and harm. Public health coordination is essential.

Reference: NACI measles post-exposure guidance 2025