Seasonal Influenza Prevention & Control

2023-2024 Influenza Season

The influenza vaccine recommendations change every year. In addition to communicating these updates, AAFP recommends offering annual flu shots to patients 6 months and older who don't have contraindications for the immunization.

In late June, ACIP released several primary updates for clinicians. Listed are several of the primary changes:

AAFP recommends that patients aged 65 years and older preferentially receive any one of the following higher doses or adjuvanted influenza vaccines: quadrivalent high-dose inactivated influenza vaccine (HD-IIV4), quadrivalent recombinant influenza vaccine (RIV4), or quadrivalent adjuvanted inactivated influenza vaccine (aIIV4). If none of these three vaccines is available at an opportunity for vaccine administration, then any other age-appropriate influenza vaccine should be used.

To protect your patients from severe illness and health complications, promote the influenza vaccination as soon as it's available each year and provide the vaccine throughout the flu season (i.e., as long as influenza viruses are circulating in the community). Vaccination is especially important as COVID-19 variants continue to spread.

As flu season approaches, your patients may have questions about getting the flu shot and COVID-19 vaccines, including any updated COVID-19 vaccines. The CDC offers updated guidance on co-administration of COVID-19 vaccines with other vaccines.

Helping You Prepare for 2023-24 Flu Season

AAFP Resources

The flu season is already shaping up to be a difficult one. We're taking action to help family physicians prepare for a potential “tripledemic” of COVID-19, influenza and respiratory syncytial virus this winter. Read more in Prepare for ‘Tripledemic’ With New and Updated AAFP Tools.

CDC Resources

FAQS: What's New for 2022-2023 Season: A few things are different for the 2022-2023 influenza (flu) season.
Information on Influenza Virus Testing, Treatment: Updated testing information and algorithms for influenza during the COVID-19 pandemic.

“Preliminary estimates indicate that influenza levels rose during the 2021-2022 season, though still lower than most previous pre-pandemic years, and there is potential for a more severe season coming up.”
- Pamela Rockwell, D.O., AAFP’s liaison to the ACIP.

Supporting Patient Flu Vaccine Conversations

These resources for family physicians were developed in partnership with Sanofi Pasteur, Inc. to promote the importance of annual influenza vaccination.

Influenza Vaccine Updates

Routine annual influenza vaccination of all persons aged ≥6 months who do not have contraindications continues to be recommended. Primary updates to this report include the following two topics:

The composition of 2023-24 U.S. seasonal influenza vaccines
Updated recommendations regarding influenza vaccination of persons with egg allergy

The composition of 2023-24 U.S. influenza vaccines includes an update to the influenza A(H1N1)pdm09 component. U.S.-licensed influenza vaccines will contain HA derived from 1) an influenza A/Victoria/4897/2022 (H1N1)pdm09-like virus (for egg-based vaccines) or an influenza A/Wisconsin/67/2022 (H1N1)pdm09-like virus (for cell culture-based and recombinant vaccines); 2) an influenza A/Darwin/9/2021 (H3N2)-like virus (for egg-based vaccines) or an influenza A/Darwin/6/2021 (H3N2)-like virus (for cell culture-based and recombinant vaccines); 3) an influenza B/Austria/1359417/2021 (Victoria lineage)-like virus; and 4) an influenza B/Phuket/3073/2013 (Yamagata lineage)-like virus.
ACIP recommends that all persons aged ≥6 months with egg allergy should receive influenza vaccine. Any influenza vaccine (egg based or nonegg based) that is otherwise appropriate for the recipient’s age and health status can be used. It is no longer recommended that persons who have had an allergic reaction to egg involving symptoms other than urticaria should be vaccinated in an inpatient or outpatient medical setting supervised by a health care provider who is able to recognize and manage severe allergic reactions if an egg-based vaccine is used. Egg allergy alone necessitates no additional safety measures for influenza vaccination beyond those recommended for any recipient of any vaccine, regardless of severity of previous reaction to egg. All vaccines should be administered in settings in which personnel and equipment needed for rapid recognition and treatment of acute hypersensitivity reactions are available.
On the basis of review of evidence concerning high-dose inactivated influenza vaccine (HD-IIV), recombinant influenza vaccine (RIV), and MF59-adjuvanted inactivated influenza vaccine (aIIV), recommendations for influenza vaccination of persons aged ≥65 years have been modified. ACIP recommends that adults aged ≥65 years preferentially receive any one of the following higher dose or adjuvanted influenza vaccines: quadrivalent high-dose inactivated influenza vaccine (HD-IIV4), quadrivalent recombinant influenza vaccine (RIV4), or quadrivalent adjuvanted inactivated influenza vaccine (aIIV4). If none of these three vaccines is available at an opportunity for vaccine administration, then any other age-appropriate influenza vaccine should be used. Higher dose vaccines include HD-IIV4 and RIV4, both of which contain a higher dose of HA antigen per virus than standard-dose vaccines (60 µg for HD-IIV4 and 45 µg for RIV4, compared with 15 µg for standard-dose inactivated vaccines). Adjuvanted inactivated influenza vaccine (aIIV4) contains MF59 adjuvant.

Influenza Vaccine Additional Recommendations

Populations at Higher Risk for Medical Complications Attributable to Severe Influenza

All persons aged ≥6 months who do not have contraindications should be vaccinated annually. However, vaccination to prevent influenza is particularly important for persons who are at increased risk for severe illness and complications from influenza and for influenza-related outpatient, emergency department, or hospital visits. When vaccine supply is limited, vaccination efforts should focus on vaccination of persons at higher risk for medical complications attributable to severe influenza who do not have contraindications. These persons include the following (no hierarchy is implied by order of listing):

All children aged 6 through 59 months.
All persons aged ≥50 years.
Adults and children who have chronic pulmonary (including asthma), cardiovascular (excluding isolated hypertension), renal, hepatic, neurologic, hematologic, or metabolic disorders (including diabetes mellitus).
Persons who are immunocompromised due to any cause (including but not limited to immunosuppression caused by medications or HIV infection).
Persons who are or will be pregnant during the influenza season.
Children and adolescents (aged 6 months through 18 years) who are receiving aspirin- or salicylate-containing medications and who might be at risk for experiencing Reye syndrome after influenza virus infection.
Residents of nursing homes and other long-term care facilities.
American Indian or Alaska Native persons.
Persons who are extremely obese (body mass index ≥40 for adults).