The Advisory Committee on Immunization Practices (ACIP) for the U.S. Centers for Disease Control and Prevention (CDC) has issued new updates for influenza vaccines for 2020–2021 “flu season,” primarily for Fluzone and Fluad vaccines.
In November 2019, U.S. Food and Drug Administration (FDA) licensed inactivated injectable Fluzone High-Dose Quadrivalent (HD-IIV4) for use in persons aged 65 years and older. For the 2020–2021 season, Fluzone High-Dose Quadrivalent is expected to replace the previously available trivalent formulation of Fluzone High-Dose (HD-IIV3).
The dose volume for Fluzone High-Dose Quadrivalent (0.7 mL) is slightly higher than that of trivalent Fluzone High-Dose (0.5 mL). Fluzone High-Dose Quadrivalent, like Fluzone High-Dose, contains four times the amount of viral hemagglutinin (HA) per vaccine virus in each dose compared with standard-dose inactivated influenza vaccines.2
In February 2020, the FDA licensed inactivated injectable Fluad Quadrivalent (aIIV4). Fluad Quadrivalent is approved for use in persons aged 65 years and older. For the 2020–2021 season, both Fluad Quadrivalent and the previously licensed trivalent formulation of Fluad (aIIV3) are expected to be available. Like Fluad, the quadrivalent version of Fluad contains a squalene based MF59 adjuvant.3
The National Vaccine Information Center (NVIC) has pointed out that squalene adjuvants have not been tested compared to placebos in large trials published in scientific journals. In addition, there are no studies specifically evaluating cellular, molecular and DNA changes in the body after squalene-adjuvanted vaccines have been administered to children and adults.4
In a public comment in 2015, Barbara Loe Fisher, co-founder and president of NVIC said, “Squalene adjuvants hyper-stimulate the immune system and have been linked with development of autoimmunity, narcolepsy and other chronic disease.”5
Updates to the Composition of All Influenza Vaccines
The ACIP guidelines also include updates to the composition of trivalent and quadrivalent influenza vaccines for the 2020-2021 season for all ages, which includes influenza A(H1N1)pdm09, influenza A(H3N2) and influenza B/Victoria lineage components. The updated components will be included in both trivalent and quadrivalent vaccines. Quadrivalent vaccines will include an additional influenza B virus component from the B/Yamagata lineage, which is unchanged from that included in quadrivalent influenza vaccines used during the 2019–2020 season.6
For the 2020–2021 season, the following influenza vaccines will available:
Egg-based influenza vaccines:
- Will contain hemagglutinin derived from an influenza A/Guangdong-Maonan/SWL1536/2019 (H1N1)pdm09-like virus; an influenza A/Hong Kong/2671/2019 (H3N2)-like virus; and an influenza B/Washington/02/2019 (Victoria lineage)-like virus.
- Quadrivalent vaccines will include an influenza B/Phuket/3073/2013 (Yamagata lineage)-like virus as well.
- These vaccines include Afluria Quadrivalent, Fluarix Quadrivalent, FluLaval Quadrivalent, Fluzone Quadrivalent (all standard dose), Fluzone High-Dose Quadrivalent (high-dose formulation), Fluad Quadrivalent (standard dose with MF59 adjuvant), Fluad (standard dose trivalent vaccine with MF59 adjuvant) and FluMist Quadrivalent live virus intranasal spray.7
Cell culture based inactivated and recombinant influenza vaccines:
- Will contain hemagglutinin derived from an influenza A/Hawaii/70/2019 (H1N1)pdm09-like virus; an influenza A/Hong Kong/45/2019 (H3N2)-like virus; an influenza B/Washington/02/2019 (Victoria lineage)-like virus; and an influenza B/Phuket/3073/2013 (Yamagata lineage)-like virus.
- These vaccines include Flucelvax Quadrivalent (standard dose cell culture based) and Flublok Quadrivalent (recombinant).
By Sept. 3, 2020, the FDA reported that more than 235 lots of influenza vaccine had been released by the FDA for distribution by six vaccine manufacturers, including Seqirus, GlaxoSmithKline, Protein Sciences, ID Biomedical Corporation of Quebec, MedImmune and Sanofi Pasteur.8 9
1 Grohskopf L. et al. Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices — United States, 2020–21 Influenza Season. MMWR 2020; 69(8): 1–24.
4 La Vigne P. FDA Approves Experimental H5N1 Bird Flu Vaccine with Reactive AS03 Adjuvant for U.S. Stockpile. National Vaccine Information Center Dec. 9, 2013.
5 Fisher BL. FDA Fast-Tracks Licensure of MF59 Adjuvanted Influenza Vaccine. NVIC Sept. 16, 2015.
6 See Footnote 1.
8 U.S. Food and Drug Administration. Influenza Vaccine for the 2020-2021 Season. Sept. 3, 2020.
9 FDA. Vaccines Licensed for Use in the United States. Apr. 24 2020.