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August 29, 2023

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2022-2023 Influenza Season CDC Recommendations

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The information below is taken directly from the CDC site and hyperlinks are imbedded in the titles or
at the end.

Timing of Influenza Vaccination

For the 2022-2023 flu season, the CDC’s recommendation on timing of vaccinations is similar to last season. For most people, the CDC and ACIP recommend vaccination by the end of October.

• “Vaccinating early – for example, in July or August – may lead to reduced protection against
influenza later in the season, particularly among older adults.”
• September/October remain good times for vaccination, and as long as viruses circulating,
vaccination should continue even into January or later. (1)

What flu vaccines are recommended this season?

For the 2022-2023 flu season, the CDC recommends annual influenza vaccination for everyone 6 months and older with any licensed, age-appropriate flu vaccine (IIV, RIV4 or LAIV4) with no preference expressed for any one vaccine over another. The composition of flu vaccines has been updated. For details, please visit here (2).

Three flu vaccines are preferentially recommended for people 65 years and older:

• Fluzone High-Dose Quadrivalent vaccine
• Flublok Quadrivalent recombinant flu vaccine
• Fluad Quadrivalent adjuvanted flu vaccine

Upcoming Influenza Season

The recommendations for the 2022-2023 season include two updates, compared with the recommended composition of last season’s U.S. flu vaccines. Both the influenza A (H3N2) and the influenza B (Victoria lineage) vaccine virus components were updated. For the full vaccine composition, please visit the CDC website (3).

Differential Diagnosis COVID-19 verses Influenza

Using clinical findings may be helpful in some initial management decisions but not in the differential diagnosis of either disease. Clinical testing with a molecular-based method is recommended for both COVID-19 and influenza when patients meet criteria for testing.

Influenza Testing During COVID-19

Molecular testing should be used for definitive detection of influenza virus infections in clinical environments. Most patients with significant influenza like illness (ILI) and underlying risk factors should be tested for both influenza and SARS-Cov-2. According to some authorities, if influenza is in low circulation this season, testing for SARS-Cov-2 should probably take precedence over influenza testing for patients with ILI in the outpatient setting.

Co-Infections with SARS-Cov-2 and Influenza

Clinicians should maintain a wide differential for potential co-infective pathogens because influenza A and B are not the only respiratory pathogens circulating in higher prevalence during the fall and winter months. Co-infections with influenza of any type are known to increase complication rates and possibly mortality. Each co-infecting pathogen and underlying medical condition should be directly managed using clinically appropriate therapy, including the best validated therapy available. The influenza vaccine plays a crucial role in influenza prevention and public health measures, both of which should be promoted by clinicians in their practice.

Influenza Vaccine During COVID-19

You can receive the COVID-19 vaccine and flu vaccine at the same time if you are eligible and the timing coincides.
• Positive COVID-19 symptomatic patients should wait until symptoms resolve to receive influenza vaccine.
• Positive COVID-19 asymptomatic patients should wait five days (pre-symptomatic phase) from test date.

How do I prepare and/or manage my facility for a flu outbreak?

Preventing transmission of influenza viruses and other infectious agents within health care settings, including long-term care facilities, requires a multi-faceted approach that includes Vaccination Testing, Infection Control, Antiviral Treatment and Antiviral Chemoprophylaxis. The information below is also found in the hyperlink at the end.

Vaccination – Influenza vaccinations should be provided routinely to all residents and health care workers of long-term care facilities.

Testing – Even if it’s not influenza season, influenza testing should occur when any resident has signs and symptoms that could be due to influenza and especially when two residents or more develop respiratory illness within 72 hours of each other.

Infection Control – Implement daily active surveillance for respiratory illness among ill residents, health care personnel and visitors to the facility. If 2 cases of laboratory-confirmed influenza are identified within 72 hours of each other on the same unit, outbreak control measures should be implemented. Implement Standard and Droplet Precautions (4) for all residents with suspected or confirmed influenza.

Antiviral Treatment – Administer influenza antiviral treatment and chemoprophylaxis to residents and health care personnel according to current recommendations. All long-term care facility residents who have confirmed or suspected influenza should receive antiviral treatment immediately and should not wait for laboratory confirmation of influenza. Antiviral treatment works best when started within the first 2 days of symptoms. However, these medications can still help when given after 48 hours to those who are very sick, such as those who are hospitalized or who have progressive illness.

    • Four influenza antiviral drugs approved by the U.S. Food and Drug Administration are recommended for use in the United States:
      • Oral Oseltamivir (available as generic version or trade name Tamiflu®), pill or suspension, recommended dose bid x 5d; treatment for people of all ages.
      • Zanamivir (trade name Relenza®), available as an inhaled powder using a disk inhaler device. Zanamivir should be used when persons require chemoprophylaxis as a result of exposure to influenza virus strains that are suspected or known to be Oseltamivir-resistant. It should be noted that some ong-term care residents may have difficulty using the inhaler device for Zanamivir. Recommended dose bid x 5d.
      • Intravenous peramivir (trade name Rapivab®).
      • Baloxavir marbosil trade name Xofluza, approved for early treatment of uncomplicated influenza in people 12 yrs. and older who are otherwise healthy or at high-risk for influenza complications. A single dose of oral Baloxavir is equivalent to 5 days of bid daily oral Oseltamivir.
      • Dosage adjustment may be required for children and persons with certain underlying conditions. Clinicians should consult the manufacturers’ package insert for approved ages, recommended drug dosing adjustments and contraindications.
    • Persons whose need for antiviral chemoprophylaxis is attributed to potential exposure to a person with laboratory-confirmed influenza should receive oral Oseltamivir or inhaled Zanamivir.
    • Amantadine and rimantadine are NOT recommended for use because of high levels of antiviral resistance among circulating influenza A viruses.


  • Antiviral Chemoprophylaxis – All eligible residents in the entire long-term care facility (not just currently impacted wards) should receive antiviral chemoprophylaxis as soon as an influenza outbreak is determined. When at least 2 patients are ill within 72 hours of each other and at least one resident has laboratory-confirmed influenza, the facility should promptly initiate antiviral chemoprophylaxis to all non-ill residents, regardless of whether they received influenza vaccination during the previous fallseason. Priority should be given to residents living in the same unit or floor as the ill resident. However, since staff and residents may spread influenza to residents on other units, floors or buildings of the same facility, all non-ill residents are recommended to receive antiviral chemoprophylaxis to control influenza outbreaks.
    • Antiviral chemoprophylaxis is recommended for all non-ill residents in long-term care facilities that are experiencing outbreaks, regardless of their influenza vaccination status.
    • Antiviral chemoprophylaxis is meant for patients and residents who are not exhibiting influenza-like illness but who may be exposed or who may have been exposed to an ill person with influenza, to prevent transmission.
    • Use of antiviral drugs for chemoprophylaxis of influenza is a key component of influenza outbreak control in institutions that house residents at higher risk of influenza complications.
    • While highly effective, antiviral chemoprophylaxis is not 100% effective in preventing influenza illness. CDC recommends antiviral chemoprophylaxis for a minimum of 2 weeks and continuing for at least 7 days after the last known case was identified (5).


  1. Frequently Asked Influenza (Flu) Questions: 2022-2023 Season | CDC
  2. Influenza Activity and Composition of the 2022–23 Influenza Vaccine — United States, 2021–22 Season | MMWR (
  3. CDC Data Centres – CDC provides state-of-the-art, secure, modular, connected and sovereign hosting facilities to public and private sector organisations throughout Australia and New Zealand.
  4. Isolation Precautions | Guidelines Library | Infection Control | CDC
  5. Interim Guidance for Influenza Outbreak Management in Long-Term Care and Post-Acute Care Facilities | CDC