What are the current evidence-based recommendations for seasonal influenza and COVID-19 (Coronavirus Disease 2019) vaccinations for healthy children and adults?

Current Evidence-Based Recommendations for Seasonal Influenza and COVID-19 Vaccination for Healthy Children and Adults

Annual influenza vaccination is recommended for all individuals aged ≥6 months, and COVID-19 vaccination is recommended for all persons aged ≥6 months, with specific dosing regimens based on age and vaccination history. 1, 2

Influenza Vaccination Recommendations

For Children:

• All children aged ≥6 months should receive annual influenza vaccination, ideally by the end of October 1

• Children aged 6 months through 8 years receiving influenza vaccine for the first time or who have received only 1 dose before July 1,2021, or whose vaccination status is unknown, should receive 2 doses of influenza vaccine administered 4 weeks apart 1

• Children who have previously received ≥2 doses of trivalent or quadrivalent influenza vaccine before July 1,2022 (doses need not have been received during the same or consecutive seasons) require only 1 dose of the 2022-23 influenza vaccine 1

• For children aged 6 through 35 months, the following dose volumes are recommended 1:

  • Afluria Quadrivalent: 0.25 mL per dose
  • Fluarix Quadrivalent: 0.5 mL per dose
  • Flucelvax Quadrivalent: 0.5 mL per dose
  • FluLaval Quadrivalent: 0.5 mL per dose
  • Fluzone Quadrivalent: either 0.25 mL or 0.5 mL per dose

• Children aged ≥36 months (≥3 years) should receive a 0.5 mL dose of any available, licensed, age-appropriate vaccine 1

• Healthy children aged ≥24 months (≥2 years) may receive either inactivated influenza vaccine (IIV) or live attenuated influenza vaccine (LAIV), with no preference for one formulation over another 1

For Adults:

• All adults should receive annual influenza vaccination, with particular focus on those at higher risk for complications 1, 2

• Adults aged ≥65 years may receive any age-appropriate IIV or the recombinant influenza vaccine (RIV4) 2

• High-dose inactivated influenza vaccine (HD-IIV4) and adjuvanted inactivated influenza vaccine (aIIV4) are approved only for adults aged ≥65 years 1

Special Considerations:

• Vaccination should continue to be offered as long as influenza viruses are circulating and unexpired vaccine is available 1

• Persons who have had laboratory-confirmed influenza should still receive annual influenza vaccination according to recommendations, as infection with one virus type or subtype does not confer immunity to other types or subtypes 3

• Individuals with moderate to severe acute illness should defer vaccination until their symptoms have improved 1

COVID-19 Vaccination Recommendations

• COVID-19 vaccination is recommended for all persons aged ≥6 months 2

• COVID-19 vaccines can be administered concurrently with influenza vaccines at different anatomical sites 4

• When administering vaccines with increased reactogenicity (e.g., adjuvanted or high-dose influenza vaccines) along with COVID-19 vaccines, they should be injected into different limbs 4

Contraindications and Precautions

For Influenza Vaccines:

• IIV should not be administered to:

  • Infants younger than 6 months 1
  • Individuals with severe allergic reactions to previous influenza vaccines or vaccine components 1

• LAIV should not be administered to:

  • Children younger than 2 years 1
  • Children with asthma or history of wheezing 1
  • Children with chronic underlying medical conditions 1
  • Pregnant women 1
  • Persons who care for severely immunocompromised individuals requiring a protected environment (should avoid contact for 7 days after receiving LAIV) 1

For COVID-19 Vaccines:

• Persons who have tested positive for COVID-19 or who are in quarantine should defer vaccination until they have recovered to avoid exposing others 1

Timing Considerations

• Vaccination should ideally occur before the onset of influenza activity in the community, preferably by the end of October 1

• Studies have shown decreasing vaccine effectiveness with increasing time post-vaccination within a single influenza season, with waning effects varying by age group, influenza virus type, and season 1

• Influenza and COVID-19 vaccines can be administered simultaneously at different anatomic sites, which can improve vaccination coverage and efficiency 4

Common Pitfalls to Avoid

• Delaying vaccination to administer vaccines separately when they can be given simultaneously may lead to missed opportunities for vaccination 4

• Failing to recognize that children aged 6 months through 8 years may need two doses of influenza vaccine depending on their vaccination history 1

• Unnecessarily delaying vaccination after recovery from influenza or COVID-19 infection may leave individuals vulnerable during peak respiratory virus season 3

• Not recognizing that influenza vaccination is still beneficial even in years with suboptimal vaccine effectiveness, as it can still prevent serious outcomes such as hospitalization, ICU admission, or death 5