What is the recommended dose for the influenza (flu) virus vaccine?

Influenza Vaccine Dosing Recommendations

The recommended dose of influenza vaccine depends on age and vaccination history: children 6-35 months receive either 0.25 mL or 0.5 mL depending on the specific vaccine product, children ≥36 months and adults receive 0.5 mL, and adults ≥65 years receive either 0.5 mL (standard dose) or 0.7 mL (high-dose formulation). 1

Dose Volume by Age Group

Children 6-35 Months

The dose volume varies by vaccine brand for this age group 1:

• Afluria: 0.25 mL per dose (7.5 μg HA per virus) 1
• Fluarix: 0.5 mL per dose (15 μg HA per virus) 1
• Flucelvax: 0.5 mL per dose (15 μg HA per virus) 1
• FluLaval: 0.5 mL per dose (15 μg HA per virus) 1
• Fluzone: Either 0.25 mL or 0.5 mL per dose (both acceptable) 1

Important caveat: The 0.25 mL prefilled syringes are no longer widely available for most products, so the appropriate volume must be drawn from multidose vials when a 0.25 mL dose is indicated 1.

Children ≥36 Months Through Adults <65 Years

• Standard dose: 0.5 mL per dose (15 μg HA per virus) for all inactivated influenza vaccines 1
• Live attenuated vaccine (LAIV): 0.2 mL intranasally (0.1 mL per nostril) for ages 2-49 years 1
• Recombinant vaccine (RIV): 0.5 mL per dose (45 μg HA per virus) for ages ≥18 years 1

Adults ≥65 Years

• Standard dose: 0.5 mL per dose 1
• High-dose vaccine (Fluzone High-Dose): 0.7 mL per dose (60 μg HA per virus, 180 μg total) 1
• Adjuvanted vaccine (Fluad): 0.5 mL per dose (15 μg HA per virus with MF59 adjuvant) 1

Number of Doses Required

Children 6 Months Through 8 Years

The number of doses depends on prior vaccination history 1:

• One dose needed: Children who have previously received ≥2 total doses of influenza vaccine (trivalent or quadrivalent) ≥4 weeks apart before July 1 of the current season 1

  • The 2 previous doses do not need to have been received in the same season or consecutive seasons 1

• Two doses needed: Children who have not previously received ≥2 doses ≥4 weeks apart, or whose vaccination history is unknown 1

  • Doses must be administered ≥4 weeks apart 1
  • Both doses should be given even if the child turns 9 years between dose 1 and dose 2 1
  • First dose should be given as soon as vaccine is available to allow the second dose to be received by end of October 1

Evidence supporting two-dose schedule: A 2025 meta-analysis found that receiving 2 doses of inactivated influenza vaccine was associated with a 28 percentage point increase in vaccine effectiveness for children <3 years compared to one dose, though this benefit was not statistically significant when extended to children <9 years 2.

Children ≥9 Years and Adults

• One dose per season regardless of vaccination history 1

Dosing Error Correction

If an incorrect dose volume is administered 1:

• Underdosing in children ≥36 months: If a smaller dose (e.g., 0.25 mL) is inadvertently given, administer the remaining volume during the same visit, or if measuring is challenging, give a full 0.5 mL dose 1
• If error discovered after patient leaves: Administer a full 0.5 mL dose as soon as the patient can return 1
• Adult formulation given to child: Count as a valid single dose 1

Route of Administration

• Inactivated vaccines: Intramuscular injection 1
  • Deltoid muscle preferred for adults and older children 1
  • Anterolateral thigh for infants and younger children 1
• Live attenuated vaccine: Intranasal spray 1

Special Populations

Pregnant Persons

• Any licensed, age-appropriate inactivated or recombinant vaccine at standard adult dose (0.5 mL) 1
• LAIV should not be used during pregnancy 1
• Can be administered at any time during pregnancy 1

Immunocompromised Persons

• Standard dosing applies 1
• LAIV should not be used 1
• Solid organ transplant recipients aged 18-64 years on immunosuppressive medications may receive high-dose or adjuvanted vaccines without preference over standard-dose vaccines 1