Learn about the selected strains for this year’s flu season, flu vaccine recommendation changes, and newly licensed and forthcoming vaccine options
Now more than ever, it’s essential for patients— particularly those who are at risk—to be vaccinated against influenza. Adults 65 and older, individuals with comorbidities, people of color, and individuals of lower socioeconomic status are at higher risk of illness. Getting vaccinated helps protect these vulnerable populations.
The 2022-2023 Flu Season
What strains have been chosen for this season’s vaccines?
On February 25, 2022, the World Health Organization (WHO) announced the strains selected for the 2022-2023 flu season vaccines after reviewing the data of circulating virus (see sidebar).1
On March 3, 2022, the FDA’s Vaccines and Related Biological Products Advisory Committee voted to approve the strains selected by WHO.2
What are the new recommendations for the current flu season?
At a meeting in June 2022, the Advisory Committee on Immunization Practices recommended that adults 65 and older receive high-dose influenza vaccines for better protection.3 These vaccines include quadrivalent adjuvanted inactivated influenza vaccine (aIIV4), quadrivalent high-dose inactivated influenza vaccine (HD-IIV4), or quadrivalent recombinant influenza vaccine (RIV4).3
New and Forthcoming Vaccines
In May 2021, the FDA approved the cell-based vaccine Flucelvax (Seqirus).4 This extends the age of coverage of the vaccine to children 6 months and older. A phase 3 clinical study supported this approval, showing that the vaccine’s safety and immunogenicity was equivalent to that of other standard quadrivalent vaccines for children of ages 6 months to 5 years.4 “These data, presented at the Pediatric Academic Societies 2021 Virtual Meeting on May 1, 2021, represent the first US phase 3 study of a cell- based influenza vaccine in this population,” the press release noted.4
Moderna is conducting ongoing clinical trials for its mRNA-1230 combination vaccine, which is designed to protect against influenza, COVID-19, and respiratory syncytial virus using the company’s mRNA platform. In a press release distributed ahead of the company’s annual Vaccines Day— held this year in March 2022—Stephen Hoge, MD, president of Moderna said, “We are pleased to add a combination respiratory vaccine candidate against 3 of the leading causes of respiratory disease in older adults, and a vaccine against all 4 of the endemic human coronaviruses as part of our strategy to address the substantial global burden of respiratory infections....Our goal is to develop vaccines to address respiratory infections and eventually combine many into a single annual booster vaccine, with the aim of reducing the significant morbidity and mortality caused by these viruses.”5
On July 1, 2022, the FDA approved the license for Sanofi’s Fluzone High-Dose Quadrivalent, Flublok Quadrivalent, and Fluzone Quadrivalent influenza vaccines for the 2022-2023 season. Fluzone and Flublok are the only influenza vaccines proven by randomized controlled trials to prevent more cases in older adults, according to Sanofi’s press release.6 Sanofi said Fluzone has 10 years of evidence in protecting adults 65 and older from flu-related hospitalizations.
“In a clinical study, Flublok Quadrivalent is the first and only recombinant influenza vaccine for adults 18 [and older] that was proven to be 30% more effective than a standard-dose vaccine at preventing flu infection in over 9000 adults 50 [and older]. In adults 50 [and older], the most common [adverse] effects were tenderness and/or pain at the injection site, headache, and tiredness,” the press release stated.6
Finally, Novavax, Inc, is developing a COVID-19–influenza combination vaccine. In April 2022, Novavax reported the vaccine was well tolerated and immunogenic, and that the phase 2 confirmation trial will begin toward the end of 2022.7 In the news release, Gregory M. Glenn, MD, president of research and development at Novavax, said the company is continuing “to evaluate the dynamic public health landscape and believes there may be a need for recurrent boosters to fight both COVID-19 and seasonal influenza. We’re encouraged by these data and the potential path forward for a combination COVID-19 influenza vaccine [and] stand-alone vaccines for influenza and COVID-19.”7
1. Recommendations announced for influenza vaccine composition for the 2022-2023 northern hemisphere influenza season. News release. World Health Organization; February 25, 2022. Accessed July 5, 2022. https://www.who.int/news/item/25-02-2022-recommendations-announced-for-influenza-vaccine-composition-for-the-2022-2023-northern-hemisphere-influenza-season.
2. Vaccines and Related Biological Products Advisory Committee March 3, 2022 meeting announcement. FDA. Updated March 25, 2022. Accessed July 5, 2022. https://www.fda.gov/advisory-committees/advisory-committee-calendar/vaccines-and-related-biological-products-advisory-committee-march-3-2022-meeting-announcement
3. ACIP flu meeting update: Flu vaccines worked better than reported & ACIP recommends specific vaccines for seniors. CDC. Published June 23, 2022. Accessed July 19, 2022. https://www.cdc.gov/flu/spotlights/2021-2022/specific-vaccines-seniors.htm
4. Seqirus receives FDA approval of its cell-based quadrivalent influenza vaccine, expanding the age indication to include children as young as six months. News release. Seqirus; October 15, 2021. Accessed July 5, 2022. https://www.prnewswire.com/news-releases/seqirus-receives-fda-approval-of-its-cell-based-quadrivalent-influenza-vaccine-expanding-the-age-indication-to-include-children-as-young-as-six-months-301401332.html
5. Moderna announces new development programs ahead of 3rd annual Vaccines Day. News Release. Moderna; March 22, 2022. Accessed July 5, 2022. https://investors.modernatx.com/news/news-details/2022/Moderna-Announces-New-Development-Programs-Ahead-of-3rd-Annual-Vaccines-Day/default.aspx
6. Sanofi flu vaccines licensed and approved for 2022-2023 influenza season, including CDC preferred higher-dose vaccines for adults 65+. News release. Sanofi; July 1, 2022. Accessed July 5, 2022. https://www.prnewswire.com/news-releases/sanofi-flu-vaccines-licensed-and-approved-for-2022-2023-influenza-season-including-cdc-preferred-higher-dose-vaccines-for-adults-65-301579875.html
7. Initial results from Novavax’ COVID-19-influenza vaccine trial are first to show feasibility of combination vaccine. News Release. Novavax Inc; April 20, 2022. Accessed July 5, 2022. https://www.prnewswire.com/in/news-releases/initial-results-from-novavax-covid-19-influenza-vaccine-trial-are-first-to-show-feasibility-of-combination-vaccine-839902859.html