1) For infants and young children, the most appropriate injection site for pneumococcal conjugate vaccine (PCV) and pentavalent vaccine (Penta) is the vastus lateralis muscle in the anterolateral thigh.
Vastus lateralis
- Origin: Greater trochanter and linea aspera of femur
- Insertion: Patella through the quadriceps tendon, and tibial tuberosity through the patellar ligament
- Action: Extends the leg at knee joint
To locate this site of injection,
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Locate the greater trochanter and patella.
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Between these two anatomical landmarks, draw a vertical imaginary line down the middle of the thigh.
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Imagine the thigh is divided into three equal parts horizontally.
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The correct injection site Is located in the middle third, on the outside portion of the imaginary line.
2) For the 65-year-old patient, the preferred intramuscular injection site for influenza vaccination is the deltoid muscle in the upper arm.
Deltoid
- Origin: Acromial extremity of clavicle (anterior fibers), acromion of scapula (lateral fibers), and spine of scapula (posterior fibers)
- Insertion: Deltoid tuberosity of humerus
- Action: Lateral fibers abduct arm at shoulder joint, anterior fibers flex and medially rotate arm at shoulder joint, and posterior fibers extend and laterally rotate arm at shoulder joint
To locate this site of injection,
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Locate the acromion process by palpating the bony prominence from the shoulder.
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Lay three fingers below the acromion process.
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The correct injection site is located generally three finger widths below the acromion process, in the middle of the deltoid muscle.