Which of the following is an absolute contraindication to the administration of live attenuated vaccines?

Explanation

## Absolute Contraindications to Live Vaccines **Key Point:** Live attenuated vaccines are contraindicated in severely immunocompromised individuals because the vaccine strain itself can cause disease. ### Immunocompromised States — Absolute Contraindications | Condition | Mechanism | Live Vaccine Safe? | |-----------|-----------|-------------------| | SCID | Complete absence of T and B cell function | **No** — vaccine strain replicates unchecked | | DiGeorge syndrome (22q11 deletion) | T cell deficiency | **No** | | X-linked agammaglobulinemia | B cell deficiency | **No** | | HIV with CD4 <200 cells/μL | Severe T cell depletion | **No** | | Active malignancy on chemotherapy | Bone marrow suppression | **No** | | Organ transplant recipients (on immunosuppression) | Pharmacological immunosuppression | **No** | ### Conditions That Are NOT Contraindications - Mild to moderate illness (including URTI) - Concurrent antibiotic use - Family history of adverse reactions - Mild local reactions to previous doses - Jaundice, diarrhea, or low-grade fever **High-Yield:** SCID is the classic example of absolute contraindication to live vaccines. The vaccine strain (e.g., rotavirus, varicella, MMR) can replicate and cause vaccine-strain disease in the absence of immune control. **Clinical Pearl:** In India, infants with suspected SCID should NOT receive rotavirus vaccine (RotaTeq or Rotavac) or other live vaccines until immune reconstitution is confirmed. **Mnemonic:** **SCID = Stop live vaccines** — the acronym itself is a reminder that Severe Combined Immunodeficiency is the prototypical contraindication. ## Why Other Options Are Wrong - **Mild URTI:** Temporary deferral is recommended, but it is NOT an absolute contraindication. Vaccination can proceed if the child is clinically well. - **Antibiotic use:** Does not impair immune response or increase vaccine-strain replication risk. - **Family history of reactions:** Does not contraindicate vaccination in the index child unless the child has a documented prior severe reaction. [cite:IAP Red Book 2023, Park 26e Ch 17]