Intradermal Flu Shot Availability
Yes, intradermal flu shots are available in the United States, specifically Fluzone Intradermal (now called Fluzone Intradermal Quadrivalent), which is FDA-approved for adults aged 18 through 64 years. 1
Product Specifications
Fluzone Intradermal contains a reduced dose of hemagglutinin compared to standard intramuscular vaccines:
- Contains 9 μg of hemagglutinin per vaccine virus strain (36 μg total for quadrivalent formulation) 1
- Standard intramuscular vaccines contain 15 μg per strain for comparison 1
- Administered as a 0.1 mL injection using a specialized microinjection delivery system 1
Administration Details
The intradermal vaccine is administered differently than traditional flu shots:
- Injected intradermally (into the skin layers, not muscle) preferably over the deltoid muscle 1
- Uses an included proprietary microinjection system with a shorter needle than standard intramuscular injections 1, 2
- Requires only a single 0.1 mL dose per season 1
Age Restrictions
This formulation has strict age limitations:
- Licensed ONLY for adults aged 18-64 years 1
- NOT approved for children, adolescents under 18, or adults 65 years and older 1
- Adults ≥65 years should receive either standard-dose intramuscular vaccine or high-dose formulations instead 1
Immunogenicity and Effectiveness
Despite the lower antigen dose, intradermal vaccination demonstrates comparable immune responses:
- Non-inferior immunogenicity compared to standard intramuscular vaccine in adults 18-59 years 3, 4
- Provides direct access to specialized dendritic cells in the skin, potentially enhancing immune response 4
- Meets European and U.S. licensing requirements for influenza vaccines 4
Common Side Effects
The intradermal route has a different side effect profile than intramuscular injection:
- More frequent injection site reactions including redness, induration, swelling, pain, and itching at the administration site 1
- Less injection site pain compared to intramuscular administration 5
- Local erythema and swelling more common with intradermal route 4
- Generally safe and well-tolerated overall 2, 3
Clinical Considerations
ACIP expresses no preference between intradermal and intramuscular formulations when both are appropriate:
- For adults 18-64 years, either intradermal or intramuscular IIV is acceptable 1
- Vaccination should not be delayed to obtain a specific product when an appropriate alternative is available 1
- The intradermal option may be preferred for patients with needle phobia due to the shorter needle 2
Important Caveat
Do not confuse intradermal flu vaccine with high-dose vaccine - these are completely different products with different age indications. High-dose Fluzone is intramuscular and approved only for adults ≥65 years, while intradermal Fluzone is approved only for adults 18-64 years. 1, 6