رضيع عمره ٤ شهور بياخذ لقاح عضلي. ما الموقع المفضل؟

A 4-month-old is due an intramuscular vaccine. Which site is preferred?

1. Deltoid muscle of the shoulder
2. Vastus lateralis (outer thigh)
3. Subcutaneous upper arm
4. Dorsogluteal muscle

Answer: B) Vastus lateralis (outer thigh). In infants the vastus lateralis is largest and safest; the deltoid is small and the dorsogluteal site risks the sciatic nerve.