Recommended Injection Site for Fluzone in a 9-Month-Old Infant
The preferred injection site for Fluzone influenza vaccine in a 9-month-old infant is the anterolateral aspect of the thigh. 1
Rationale for Site Selection
- The Advisory Committee on Immunization Practices (ACIP) specifically recommends the anterolateral aspect of the thigh as the preferred injection site for infants and young children receiving intramuscular vaccines, including Fluzone 1
- This recommendation is consistent across multiple years of ACIP guidelines, confirming the anterolateral thigh as the optimal site for infants 1
- The deltoid muscle is the recommended site for older children and adults, but is not preferred for infants due to insufficient muscle mass 1
Anatomical Considerations
- Ultrasound studies have shown that the anterolateral thigh in infants aged 6-12 months has adequate muscle thickness (mean 9.10 mm) to ensure proper intramuscular delivery 2
- The anterolateral thigh provides a larger muscle mass compared to the deltoid in infants, allowing for better absorption of the vaccine and potentially fewer adverse reactions 3
- The specific location should be at the junction of the upper and middle thirds of the anterolateral thigh to avoid major blood vessels and nerves 3
Needle Selection and Technique
- For proper intramuscular administration in the anterolateral thigh of a 9-month-old, a needle of appropriate length is essential 3
- Studies indicate that a 16 mm (5/8 inch) needle is suitable when injecting at a 90-degree angle to the skin surface 3
- If using the technique of injecting at a 45-degree angle to the skin surface, a 25 mm (1 inch) needle is recommended 3
- The injection should be administered at a 90-degree angle to ensure proper intramuscular placement 3
Special Considerations
- Ultrasound measurements have shown that in infants weighing between 3-4 kg, the mean skin-to-bone distance in the anterolateral thigh is 16.69 mm, supporting the use of a 16 mm needle 4
- For infants weighing more than 4 kg, the mean skin-to-bone distance increases to 17.04 mm 4
- The anterolateral thigh site may cause more pain and decreased movement compared to the deltoid site, but this is less relevant in 9-month-olds who are not yet walking 5
Administration Guidelines
- Fluzone is approved for children aged 6 through 35 months at either 0.25 mL or 0.5 mL per dose 1
- The site should be cleaned with an alcohol swab before administration 6
- Proper technique includes stabilizing the thigh and injecting quickly at the recommended angle 6
By following these guidelines, healthcare providers can ensure the safe and effective administration of Fluzone influenza vaccine in 9-month-old infants.