What are the guidelines for administering the flu shot?

Flu Shot Administration Guidelines

The Advisory Committee on Immunization Practices (ACIP) recommends annual influenza vaccination for all persons aged ≥6 months who do not have contraindications, with specific dose volumes and administration techniques varying by age and vaccine product. 1

Dose Volumes by Age and Product

Children 6 through 35 months:

• Afluria: 0.25 mL per dose 1
• Fluarix: 0.5 mL per dose 1
• Flucelvax: 0.5 mL per dose 1
• FluLaval: 0.5 mL per dose 1
• Fluzone: Either 0.25 mL or 0.5 mL per dose 1

Persons aged ≥36 months (≥3 years):

• All inactivated influenza vaccines: 0.5 mL per dose 1
• Exception: Fluzone High-Dose Quadrivalent (for persons aged ≥65 years): 0.7 mL per dose 1

Administration Technique

Route of Administration:

• Inactivated influenza vaccines (IIVs): Intramuscular (IM) injection 1
• Live attenuated influenza vaccine (LAIV): Intranasal spray (0.2 mL total - 0.1 mL in each nostril) 1

Injection Site:

• Adults and older children: Deltoid muscle 1
• Infants and young children: Anterolateral thigh 1

Special Administration Notes:

• One IIV (Afluria) is licensed for IM injection via the PharmaJet Stratis jet injector for persons aged 18-64 years only 1
• If a smaller vaccine dose is inadvertently administered to a person aged ≥36 months, the remaining volume should be administered during the same visit or a full dose should be given if the error is discovered later 1

Number of Doses Required

Children aged 6 months through 8 years:

• Two doses (administered ≥4 weeks apart) if:
  • Receiving influenza vaccine for the first time
  • Have not received a total of ≥2 doses of influenza vaccine before July 1 of the current season 1
• One dose if previously received ≥2 doses of influenza vaccine before July 1 of the current season 1

Persons aged ≥9 years:

• One dose annually 1, 2

Contraindications and Precautions

Contraindications:

• History of severe allergic reaction to any component of that vaccine 1
• History of severe allergic reaction to a previous dose of any influenza vaccine 1
• For LAIV: Immunosuppression, close contacts of severely immunocompromised persons, pregnancy, children aged 2-4 years with history of wheezing or asthma 1, 2

Precautions:

• Moderate or severe acute illness with or without fever (vaccination should be deferred) 1
• History of Guillain-Barré syndrome within 6 weeks of previous influenza vaccination 2
• Minor illnesses with or without fever are not contraindications 1

Timing of Vaccination

• Optimal timing: By the end of October, before influenza activity begins 2
• Vaccination should continue throughout the influenza season as long as influenza viruses are circulating 2, 3

Common Pitfalls to Avoid

1. Incorrect dosing: Ensure correct dose volume based on age and product 1
2. Improper storage: Store vaccines at 2-8°C (35-46°F) 1
3. Using previous season's vaccine: Only use current season's vaccine formulation 1
4. Delaying vaccination to obtain a specific product: Use any age-appropriate available product rather than delaying protection 2
5. Failing to identify high-risk individuals: Prioritize vaccination for pregnant women, young children, older adults, and those with chronic medical conditions 2

Effectiveness Considerations

• Vaccine effectiveness varies by season, age, and immune status 3, 4
• Even in seasons with reduced effectiveness, vaccination can still prevent serious outcomes including hospitalization and death 5
• Recent data from the 2023-24 season showed VE of 52-67% against influenza-associated medical visits in children and 33-49% in adults 3

By following these guidelines, healthcare providers can help reduce the substantial health burden of seasonal influenza through appropriate vaccination practices.