What is the recommended flu vaccine schedule for children less than a year old?

Influenza Vaccine Schedule for Children Under One Year Old

Influenza vaccine is recommended for all children 6 months of age and older, but is not recommended or approved for infants younger than 6 months of age. 1, 2

Age-Based Recommendations

• Infants younger than 6 months of age should not receive influenza vaccination as no influenza vaccines are licensed or recommended for this age group 1, 2
• Vaccination should begin at 6 months of age, which is the earliest age at which influenza vaccines are approved and recommended 3, 1
• For infants 6 months through 11 months of age, the American Academy of Pediatrics recommends annual influenza immunization 3, 4

Dosing Schedule for First-Time Recipients

• Children 6 months through 8 years of age (including infants 6-11 months) who are receiving influenza vaccine for the first time require 2 doses administered at least 4 weeks apart 1, 2
• The first dose should be administered as soon as the vaccine becomes available during influenza season 1
• The second dose should be administered at least 4 weeks after the first dose to ensure adequate immune response 1, 2
• If an infant received only 1 dose for the first time in the previous influenza season, 2 doses should be administered in the current season 3

Vaccine Formulation and Dosage

• For infants 6-11 months, only injectable inactivated influenza vaccines (IIV) are approved; live attenuated influenza vaccine (LAIV) is not approved for children under 2 years 2
• Appropriate dose volumes differ by product for infants 6-35 months 2:
  • Afluria Quadrivalent: 0.25 mL per dose 1, 2
  • Fluarix Quadrivalent: 0.5 mL per dose 1, 2
  • Flucelvax Quadrivalent: 0.5 mL per dose 1, 2
  • FluLaval Quadrivalent: 0.5 mL per dose 1, 2
  • Fluzone Quadrivalent: Either 0.25 mL or 0.5 mL per dose (both demonstrated comparable safety and immunogenicity) 1, 2

Administration Route

• For infants, the influenza vaccine is administered intramuscularly into the anterolateral thigh 1, 2
• The deltoid muscle is not recommended for infants due to insufficient muscle mass 2

Timing of Vaccination

• Vaccination should ideally begin in September or October for optimal protection during peak influenza season 2
• For infants requiring 2 doses, the first dose should be given as soon as the vaccine becomes available, even during July and August 2
• Vaccination should continue throughout the influenza season, even after influenza activity has been documented in the community 3

Special Considerations

• Household contacts and caregivers of infants younger than 6 months should be vaccinated to provide indirect protection, since these infants cannot receive the vaccine themselves 3, 5
• Pregnant women should receive influenza vaccination to potentially provide protection to infants younger than 6 months through maternal antibody transfer 5
• Infants with high-risk conditions (such as chronic medical conditions) should be prioritized for vaccination once they reach 6 months of age 1, 6

Common Pitfalls to Avoid

• Delaying the second dose beyond the recommended interval may leave the infant inadequately protected during peak influenza season 1
• Using incorrect dosage based on specific vaccine product can lead to suboptimal protection or increased side effects 1, 2
• Failing to recognize that infants under 6 months cannot receive influenza vaccine and require protection through vaccination of close contacts 5
• Not completing the two-dose series for first-time recipients, which is essential for adequate immunity 3, 1