Administration of Influvac
Influvac Tetra should be administered as a single 0.5 mL intramuscular injection in the deltoid muscle for adults and children ≥3 years, or in the anterolateral thigh for infants and young children aged 6 months and older 1, 2.
Route and Site of Administration
- Route: Intramuscular (IM) injection only
- Site selection:
- Adults and older children: Deltoid muscle
- Infants and young children (6 months to 3 years): Anterolateral aspect of the thigh 1
Dose Volume
- Standard dose: 0.5 mL per injection for all ages ≥6 months 1, 2
- Critical caveat: Some inactivated influenza vaccines (IIVs) are approved at 0.25 mL for children aged 6-35 months, but Influvac Tetra uses the standard 0.5 mL dose. Care must be taken to verify the correct dose volume for the specific vaccine product being administered 1
Dosing Schedule
The number of doses depends on the child's age and vaccination history:
Children aged 6 months through 8 years:
- Two doses (separated by at least 4 weeks) if receiving influenza vaccine for the first time or have received fewer than 2 total doses previously
- One dose if previously received ≥2 doses of influenza vaccine in prior seasons
Children ≥9 years and adults: One dose annually 1
Timing of Vaccination
- Vaccination should be offered as soon as vaccine becomes available for the season
- Should not be delayed to obtain a specific product when an appropriate vaccine is available 1
- Annual vaccination is recommended for all persons ≥6 months without contraindications 3
Important Administration Considerations
Common pitfall: Different IIV3 products have different approved dose volumes for young children (some 0.25 mL, others 0.5 mL for ages 6-35 months). Always verify the specific product's prescribing information to avoid dosing errors 1, 4.
Needle and syringe: Must be administered by needle and syringe (jet injectors are only approved for specific products in limited age ranges) 4.
Priority populations: While all persons ≥6 months should receive annual influenza vaccination, prioritize those at high risk of complications, those who can transmit to high-risk individuals, and healthcare workers 3.