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Fluzone High-Dose® (Influenza Vaccine)

Study Results

Proven to provide superior protection vs standard dose in a randomized controlled trial of patients 65+1,2*

Fluzone High-Dose is a vaccine indicated for active immunization for the prevention of disease caused by influenza A subtype viruses and type B virus contained in the vaccine. Fluzone High-Dose is approved for use in persons 65 years of age and older.

On this page, you will learn:

  • That Fluzone High-Dose reduced flu cases vs a standard-dose flu vaccine in a clinical trial of adults aged 65+1,2*

  • Fluzone High-Dose has been evaluated against standard-dose flu vaccines over 12 seasons of real-world evidence3

Pivotal Trial:

Fluzone High-Dose contains 4x the antigen and reduced flu cases by 24% vs a standard-dose flu vaccine in a clinical trial of adults aged 65+1,2*†

Study Design

  • 1:1 RCT to evaluate Fluzone High-Dose vs standard-dose Fluzone1,2
  • Study population: 31,803 adults aged 65+ during the influenza seasons 2011-2012 and 2012-20131,2
Icon showing 24% with a downward arrow

Fewer influenza cases

Primary endpoint: rVE against influenza due to ANY lab-confirmed circulating strains1,2

Icon showing 51% with a downward arrow

Fewer influenza cases

Secondary endpoint: rVE against influenza due to antigenically matched strains1,2‡

*Results from a study evaluating Fluzone High-Dose (trivalent formulation) vs Fluzone (standard-dose trivalent formulation). The prespecified statistical superiority criterion for the primary endpoint (lower limit of 2-sided 95% CI of the vaccine efficacy of Fluzone High-Dose relative to Fluzone >9.1%) was met.1,2

†Fluzone High-Dose contains 60 mcg of HA per strain vs 15 mcg of HA per strain in a standard-dose influenza vaccine.2
‡Modified CDC-defined influenza-like illness was based on the Centers for Disease Control and Prevention (CDC) surveillance network definition of an influenza-like illness and was defined as a respiratory illness with cough or sore throat, concurrent with a temperature above 37.2°C. Influenza was culture-confirmed.2

ACIP=Advisory Committee on Immunization Practices; CI=confidence interval; RCT=randomized controlled trial; rVE=relative vaccine efficacy; RWE=real-world evidence.

Real-world Evidence:

Evaluated against standard-dose flu vaccines over 12 seasons3

A Meta-analysis of:

Infographic stating more than 45 million adults aged 65+ in 21 RCTs and observational studies

Study Design3*

  • Systematic review and meta-analysis of randomized and observational studies to evaluate the rVE of Fluzone High-Dose vs standard-dose influenza vaccines against influenza-associated outcomes in more than 45 million adults aged 65+
  • Analysis included studies conducted over 12 influenza seasons (2009-2010 to 2019-2020, and 2021-2022)
    • The dominant strains were A/H3N2 and A/H1N1 in 8 and 4 of the seasons studied, respectively
    • In 8 of the 12 seasons, there was a mismatch between vaccine and circulating strains

Study Limitations3

  • High degree of statistical heterogeneity observed in several of the pooled rVE estimates
  • Inclusion of unmeasured confounders, such as health-seeking behavior or selection bias, that could affect the findings of the observational studies

*The study was supported by Sanofi; findings of the study were derived from manuscripts of 21 published studies in the public domain.3

Fluzone High-Dose prevented more influenza hospitalizations vs standard dose vaccines3

Infographic of pooled rVE for Fluzone High-Dose against influenza-related outcomes in adults

†Defined as visits with a rapid influenza diagnostic test followed by prescription of antiviral medication.3 
ER=emergency room; rVE=relative vaccine effectiveness.

Frequently asked questions

Fluzone High-Dose contains 60 mcg of hemagglutinin (HA) for each strain, for a total of 180 mcg of HA. It also contains sodium phosphate-buffered isotonic sodium chloride solution, formaldehyde, and octylphenol ethoxylate.1

Fluzone High-Dose contains 60 mcg of hemagglutinin (HA) for each strain, for a total of 180 mcg of HA.1

The most common side effects following administration of Fluzone High-Dose are pain at the injection site, myalgia, malaise, and headache.1

Fluzone High-Dose is supported by a randomized, controlled trial as well as a meta-analysis of real-world evidence.2,3

In a randomized, controlled trial conducted in 2011-2012 and 2012-2013, Fluzone High-Dose demonstrated superior vaccine efficacy vs standard-dose flu vaccine, with a 24% relative reduction in influenza cases due to any lab-confirmed strain and 51% relative reduction in influenza cases due to antigenically matched strains when compared with standard-dose vaccines.1,2

No, Fluzone High-Dose does not contain thimerosal.1

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Order Fluzone High-Dose

To order Fluzone High-Dose, call 1-800-VACCINE (1-800-822-2463) or click below to order on VaccineShop

Order on VaccineShop
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Safety Profile

The safety profile of Fluzone High-Dose compared to standard dose vaccine

See full safety data
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The Burden of Influenza

It's only the flu, until it isn't

Find out more about the complications of flu
Important Safety Information

Do not administer Fluzone, Flublok, or Fluzone High-Dose to anyone with a history of a severe allergic reaction (e.g., anaphylaxis) to any component of the vaccine (including egg protein for Fluzone and Fluzone High-Dose). Fluzone and Fluzone High-Dose should not be administered to anyone who has had a severe allergic reaction after previous dose of any influenza vaccine.

Appropriate medical treatment must be immediately available to manage potential anaphylactic reactions following administration of the vaccine.

If Guillain-Barré syndrome has occurred within 6 weeks following previous influenza vaccination, the decision to give Fluzone, Flublok, or Fluzone High-Dose should be based on careful consideration of the potential benefits and risks.

Syncope (fainting) has been reported following vaccination with Fluzone, Flublok and Fluzone High-Dose. Procedures should be in place to avoid injury from fainting.

In two separate postmarketing observational studies, an increased risk of febrile seizures was observed during the first day following vaccination with standard dose trivalent (2024-2025) and quadrivalent (2023-2024) influenza vaccines in children 6 months through 4 years of age.

If Fluzone, Flublok, or Fluzone High-Dose are administered to immunocompromised persons, including those receiving immunosuppressive therapy, the expected immune response may not be attained.

Vaccination with Fluzone, Flublok, or Fluzone High-Dose may not protect all recipients.

For Fluzone, in children 6 months through 8 years of age, the most common injection-site adverse reactions were pain or tenderness and redness; the most common solicited systemic adverse reactions were irritability, drowsiness (6 months through 35 months), and myalgia (3 years through 8 years). In adults 18 through 64 years of age, the most common injection-site adverse reaction was pain; the most common solicited systemic adverse reactions were headache and myalgia. In adults over 65 years of age, the most common injection-site adverse reaction was pain; the most common solicited systemic adverse reactions were headache, myalgia, and malaise.

For Flublok, in children 9 through 17 years of age who received Flublok Quadrivalent, the most common solicited injection-site adverse reaction was pain; the most common solicited systemic adverse reactions were myalgia, headache, and malaise. In adults 18 through 64 years of age who received Flublok, the most common injection site adverse reaction was pain; the most common solicited systemic adverse reactions were headache, fatigue, and myalgia. In adults 65 years of age and older who received Flublok, the most common injection-site adverse reaction was pain; the most common solicited systemic adverse reactions were fatigue and headache.

For Fluzone High-Dose, in adults 65 years of age and older, the most common injection-site reaction was pain; the most common solicited systemic adverse reactions were myalgia, malaise, and headache.

For Fluzone, Flublok, and Fluzone High-Dose, other adverse reactions may occur.

Indications

Fluzone, Flublok, and Fluzone High-Dose are vaccines indicated for active immunization for the prevention of disease caused by influenza A virus subtypes and type B virus contained in (or in the case of Flublok, represented by antigens contained in) the vaccine. Fluzone is approved for use in persons 6 months of age and older. Flublok is approved for use in individuals 9 years of age and older. Fluzone High-Dose is approved for use in persons 65 years of age and older.

Before administration, please see the full Prescribing Information for Fluzone, Flublok, or Fluzone High-Dose. Also, please see complete Patient Information for Fluzone or Fluzone High-Dose.

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Important Safety Information
Indications

References: 1. Fluzone High-Dose. Prescribing Information. Sanofi Pasteur Inc. 2. DiazGranados CA, et al. N Engl J Med. 2014;371(7):635-645. doi:10.1056/NEJMoa1315727 3. Lee JKH, et al. Vaccine X. 2023;14:100327. doi:10.1016/j.jvacx.2023.100327

MAT-US-2607250-v1.0-08/2026 Last updated: August 2026

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