Influenza Vaccine Administration Guidelines

Recommended Injection Sites and Techniques

The Centers for Disease Control and Prevention recommends that the influenza vaccine should not be administered in the buttocks due to potential reduced immunogenicity and risk of sciatic nerve injury 1
The intramuscular route is recommended for influenza vaccine administration, with specific anatomical sites based on age, including the deltoid muscle for adults and older children, and the anterolateral aspect of the thigh for infants and young children 2, 3, 4, 5
The Advisory Committee on Immunization Practices explicitly states that the buttock should not be used for administration of vaccines or toxoids due to potential risk of injury to the sciatic nerve and decreased immunogenicity of vaccines 1

For adults and older children receiving deltoid injections, a needle length >1 inch should be used to ensure proper muscle penetration, as recommended by the Centers for Disease Control and Prevention 6, 7
For infants receiving anterolateral thigh injections, the Advisory Committee on Immunization Practices recommends a needle length of 7/8-1 inch 8, 9
Injections must be administered at a 90-degree angle to ensure proper intramuscular placement, according to the Centers for Disease Control and Prevention 4

Deviation from the recommended route of administration might reduce vaccine efficacy or increase local adverse reactions, as stated by the Centers for Disease Control and Prevention 1
Proper intramuscular administration ensures optimal immune response to the influenza vaccine, as recommended by the Centers for Disease Control and Prevention 2, 3
Local reactions at the injection site, such as soreness and redness, are common but typically mild and short-lasting, occurring in 10-64% of patients, according to the Centers for Disease Control and Prevention 10, 8