Echographic measurement of skin thickness in sites suitable for intradermal vaccine injection in infants and children

► Measuring skin thickness improves the efficiency of intradermal vaccines. ► In children, 4 areas were studied: deltoid, suprascapular, upper back, and lumbar. ► Suprascapular skin (epidermis + dermis) was significantly thicker than deltoid skin. ► Upper back skin was significantly thicker than lumbar skin. ► Small changes with sex, age, or BMI avoid the need for area-specific microneedles.