A 4-year-old boy with acute lymphoblastic leukemia in remission is brought to the office for a well-child visit. His mother reports that he missed multiple vaccinations during chemotherapy treatment, which ended 6 months ago. His current medications include daily mercaptopurine. Laboratory studies show absolute neutrophil count 1800/mm³ and absolute lymphocyte count 1200/mm³. According to his immunization record, he has not received MMR, varicella, or DTaP vaccines since age 12 months. His oncologist confirms he is no longer severely immunocompromised. Which of the following vaccination schedules is most appropriate? Vaccine Type Minimum Age Minimum Interval Contraindication in Immunocompromise MMR Live 12 months 28 days from other live vaccine Severe immunocompromise Varicella Live 12 months 28 days from other live vaccine Severe immunocompromise DTaP Inactivated 6 weeks 4 weeks between doses None IPV Inactivated 6 weeks 4 weeks between doses None
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AAdminister MMR and varicella together today, then DTaP in 4 weeks
BAdminister MMR today, varicella in 2 weeks, and DTaP in 6 weeks
CAdminister DTaP today, then MMR and varicella together in 4 weeks
DAdminister DTaP and MMR today, then varicella vaccine in 2 weeks
EDefer all vaccinations until 12 months after chemotherapy completion
✓ Correct answer: C. Administer DTaP today, then MMR and varicella together in 4 weeksInactivated vaccines (DTaP) can be given immediately. Live vaccines (MMR, varicella) require waiting at least 3 months after severe immunosuppression ends; at 6 months post-chemotherapy, he is eligible. Live vaccines must be spaced 28 days apart if not given concurrently, so MMR and varicella should be administered together. Distractor1 violates the 28-day spacing rule for sequential live vaccines. Distractor2 incorrectly continues contraindication beyond necessary timeframe. Distractor3 inappropriately delays inactivated vaccine. Distractor4 violates live vaccine spacing requirements.
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