Vaccine Info

Flublok Quadrivalent Influenza Vaccine

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Last reviewed
December 16, 2023

FluBlok® Quadrivalent Vaccine

Flublok® is a recombinant influenza vaccine made without the use of eggs. It, therefore, is not subject to the mutations that are sometimes introduced into the vaccine during the process of egg adaptation that can cause the traditional vaccines to be ineffective. Flublok is made by Sanofi and is licensed (STN: 125285) for use in the USA by the Food and Drug Administration (FDA) and the European Medicines Agency (EMA, EMEA/H/C/005159). It has been used since 2016 and distributed to over 9 million people. The FDA considers the vaccine safe and acceptable for use. Unlike other flu vaccines, Flublok is highly purified and does not contain influenza virus, antibiotics, formaldehyde, preservatives, egg protein, latex, gluten, or gelatin. Flublok Quadrivalent is given to people 18 years of age and older.

On December 14, 2023, an Original Article published by the NEJM reported that the high-dose recombinant vaccine FluBlok conferred more protection against PCR-confirmed influenza than an egg-based standard-dose vaccine among adults between the ages of 50 and 64.

FluBlok quadrivalent is marketed in the E.U. as Supemtek. The European Commission authorized it on November 18, 2020. Visit to learn more about the potential complications of the flu, including heart attack, stroke, and pneumonia, and more about Sanofi's Flublok Quadrivalent (Influenza Vaccine). 

Sanofi Pasteur is located at 14 Espace Henry Vallée, 69007 Lyon, France.

FluBlok Quadrivalent Vaccine Price

Sanofi provides a guide for coding and reimbursement for healthcare providers. According to, the payment allowance for FluBlok in 2022-2023 is $69.94. InstantRx™ is a digital gateway empowering people to find lower-priced medicines and vaccines easily.

FluBlok Quadrivalent Indication

Flublok Quadrivalent is a vaccine given to people 18 years and older. It consists of the four influenza strains identified for the current flu season, and it contains three times the antigen of standard-dose inactivated influenza vaccines. Flublok Quadrivalent and Fluzone High-Dose Quadrivalent should not be given to anyone with a severe allergic reaction (anaphylaxis) to any vaccine component (including eggs or egg products for Fluzone High-Dose Quadrivalent).

FluBlok Quadrivalent and COVID-19 Vaccines

The US Centers for Disease Control and Prevention (CDC) issued interim clinical considerations stating that 'COVID-19 vaccines and other vaccines, including influenza vaccines, can be administered without regard to timing.

FluBlok Quadrivalent Dosage

Administer Flublok Quadrivalent as a single 0.5 mL dose intramuscular injection only.

FluBlok Quadrivalent News

September 13, 2023 - "The flu can be a serious public health threat, leading to complications such as heart attack, stroke, and pneumonia. These can be especially dangerous for older adults, ethnic and racial minority groups who are at an increased risk for being hospitalized from the flu, and those living with chronic conditions, like asthma, diabetes, and heart disease," commented Michael Greenberg, MD, MPH, North America Medical Head of Vaccines at Sanofi.

August 26, 2022 - Sanofi's Flublok® Quadrivalent Vaccine was among the flu vaccines preferentially recommended by the U.S. CDC's ACIP for adults 65+.

October 22, 2020 - Flublok has been given authorization for temporary supply by the U.K. Department of Health and Social Care and the Medicines and Healthcare products Regulatory Agency (MHRA) for immunization against flu in this year's seasonal flu program to meet public health needs. Their assessment was partly based on evidence from another closely related Sanofi flu vaccine, Supemtek. This was recommended for approval by the European Medicines Agency in September 2020. The MHRA assessment showed the two products are fundamentally similar based on a review of the manufacturing, control, quality, non-clinical, and clinical evaluation.

FluBlok Quadrivalent Clinical Trials

Flublok Quadrivalent vaccine has been studied in 29 clinical trials.

Phase 3 efficacy trial demonstrated improved protection against influenza compared to standard-dose influenza vaccine and reduced the risk of flu by an additional 30% in adults aged 50 years and older.