New Influenza Vaccine Recommendations for 2021-2022 Season

ACIP Guidance Contains Several 'Primary Updates' for Clinicians

September 16, 2021, 9:21 a.m. News Staff — The CDC’s Advisory Committee on Immunization Practices has released updated recommendations on the use of influenza vaccines for the 2021-2022 influenza season. The recommendations, published in the agency’s Morbidity and Mortality Weekly Report on Aug. 27, contain six primary updates that will be of interest to family physicians and other health care professionals, as well as comprehensive guidance for use of the vaccines in specific populations and situations.

The six primary updates are as follows.

1. All seasonal influenza vaccines expected to be available for the 2021-22 season are quadrivalent, and contain hemagglutinin derived from one influenza A(H1N1)pdm09 virus, one influenza A(H3N2) virus, one influenza B/Victoria lineage virus and one influenza B/Yamagata lineage virus.

2. The influenza A(H1N1)pdm09 and influenza A(H3N2) vaccine components have been updated. Specifically, for the 2021-2022 season, U.S. licensed influenza vaccines will contain hemagglutinin derived from an influenza A/Victoria/2570/2019 (H1N1) pdm09-like virus (for egg-based vaccines) or an influenza A/Wisconsin/588/2019 (H1N1) pdm09-like virus (for cell culture-based inactivated and recombinant influenza vaccines); an influenza A/Cambodia/e0826360/2020 (H3N2)-like virus; an influenza B/Washington/02/2019 (Victoria lineage)-like virus and an influenza B/Phuket/3073/2013 (Yamagata lineage)-like virus.

3. Flucelvax Quadrivalent, a cell culture-based inactivated influenza vaccine, is now approved for use in individuals age 2 years and older. Previously, the vaccine had been approved for individuals age 4 years and older.

4. Guidance on the administration of influenza vaccines with other vaccines has been expanded to include COVID-19 vaccination. According to the recommendations, current guidance indicates that COVID-19 vaccines can be co-administered with other vaccines, including vaccines for influenza. However, clinicians also are advised to periodically consult recommendations from the ACIP and interim clinical considerations from the CDC for the latest information.

5. Guidance on vaccination timing has been updated for certain populations:

• For patients in the third trimester of pregnancy, vaccination soon after a vaccine becomes available can now be considered.
• Children who require two doses of influenza vaccine administered four or more weeks apart should receive the first dose as soon as possible after a vaccine becomes available.
• For nonpregnant adults, influenza vaccination early in the season should be avoided unless there is concern that vaccination may not be possible later.

6. Contraindications and precautions for Flucelvax Quadrivalent (ccIIV) and recombinant influenza vaccine (RIV) have been modified:

• A previous history of severe allergic reaction such as anaphylaxis to a previous dose of any influenza vaccine, of any valency, is now considered a precaution to use of quadrivalent ccIIV or RIV rather than a contraindication. In these instances, use of quadrivalent ccIIV or RIV should occur in a medical setting under the supervision of a health care professional who can recognize and manage a severe allergic reaction; clinicians can also consider consulting with an allergist to help identify the vaccine component responsible for the reaction.
• For quadrivalent ccIIV, a history of severe allergic reaction to any ccIIV of any valency, or any component of ccIIV, is a contraindication to future use of quadrivalent ccIIV.
• For quadrivalent RIV, a history of severe allergic reaction to any RIV of any valency, or any component of RIV, is a contraindication to future use of quadrivalent RIV.

Other Items of Note

The ACIP’s recommendations also contain guidance for use of the influenza vaccine in specific populations and situations.

For example, the recommendations state that in situations where vaccine supply is limited, efforts should focus on administering the vaccine to those at increased risk for medical complications to severe influenza who do not have contraindications to being vaccinated. This includes

• all children age 6 months through 59 months and anyone 50 years and older;
• any adults and children who have chronic pulmonary (excluding asthma), cardiovascular (excluding isolated hypertension), renal, hepatic, neurologic, hematologic or metabolic disorders;
• those who are immunocompromised due to any cause;
• those who are or will be pregnant during influenza season;
• children and adolescents age 6 months through 18 years who are receiving aspirin- or salicylate-containing medications and who may be at risk of Reye syndrome after influenza virus infection;
• residents of nursing homes and other long-term care facilities;
• American Indians/Alaska Natives and;
• individuals who are extremely obese (defined in adults as a BMI of 40 or higher).

An age-appropriate quadrivalent inactivated influenza vaccine or RIV is suitable for patients in all risk groups. However, quadrivalent live attenuated influenza vaccine is not recommended for some populations.

For other populations, the ACIP’s recommendations are as follows.

Pregnant patients. Any licensed, recommended age-appropriate quadrivalent inactivated influenza vaccine or RIV may be used in patients who are pregnant or might be pregnant or postpartum during the influenza season. Quadrivalent LAIV should not be used during pregnancy, but can be used postpartum.

Older adults. For patients 65 years and older, any age-appropriate quadrivalent inactivated influenza vaccine or RIV (standard dose or high dose, adjuvanted or nonadjuvanted) is acceptable. The committee will continue to review data on the efficacy and effectiveness of influenza vaccines as more information becomes available.

Immunocompromised patients. Those with immunocompromising conditions should receive an age-appropriate quadrivalent inactivated influenza vaccine or RIV. The committee also recommends that quadrivalent LAIV should not be used in these individuals because of a biologically plausible risk for disease attributable to the vaccine.

International travelers. For travelers who want to reduce their risk for influenza, the ACIP recommends influenza vaccination at least two weeks before departure. In particular, individuals who live in the United States, are at higher risk for complications and did not receive influenza vaccine during the previous Northern Hemisphere fall or winter should consider vaccination before departure if they plan on traveling to the tropics, traveling to the Southern Hemisphere between April and September, or traveling with organized tourist groups or on cruise ships to any location.

More information on influenza vaccines and travel is available at the CDC’s Travelers’ Health Flu webpage.

The recommendations also contain additional guidance on

• administration of the vaccines in patients who have a history of Guillain-Barré  syndrome after influenza vaccination, those who have a history of egg allergy and those who have had previous allergic reactions to influenza vaccines;
• an overview on influenza dosage, administration, contraindications and precautions;
• vaccine storage and handling; and
• resources on influenza surveillance, prevention and control.

Additional Comments

Rockwell provided additional guidance for FPs who are caring for patients in an office setting.

“When administering flu shots in the office please take care to see if your patient is due or overdue for any other routine vaccines,” Rockwell said. “Pediatric and adult vaccination rates have decreased dramatically since the start of the COVID-19 pandemic, and we can start to remedy that with co-administration of influenza vaccines with other vaccines.”

“Remember that a physician recommendation has the strongest impact on our patients’ receipt of vaccines,” she added.

The ACIP is currently scheduled to hold a virtual meeting on Sept. 29 followed by a two-day meeting in October. Look to AAFP.org for relevant details from these meetings as more information becomes available.