Vaccine Info

Flublok Quadrivalent Influenza Vaccine

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Last reviewed
December 11, 2022

FluBlok Quadrivalent Vaccine Description 2022

Flublok is a recombinant influenza vaccine. Flublok is made without the use of eggs and 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 for use in the USA by the Food and Drug Administration (FDA). It has been used since 2016 and distributed to over 9 million people. The FDA considers the vaccine safe and acceptable for use. Flublok is highly purified and does not contain influenza virus, antibiotics, formaldehyde, preservatives, egg protein, latex, gluten, or gelatin, unlike other flu vaccines.

On March 3, 2022, the FDA Vaccines and Related Biological Products Advisory Committee announced the influenza vaccine strains for the 2022-2023 flu season in the Northern Hemisphere.

FluBlok quadrivalent is marketed in the E.U. as Supemtek. The European Commission authorized it on November 18, 2020. Phase 3 efficacy trial demonstrated improved protection against influenza compared to standard-dose influenza vaccine and reduced the risk of influenza by an additional 30% in adults aged 50 years and older

FluBlok Quadrivalent Vaccine Price

Sanofi provides a guide for coding and reimbursement for health care 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 that have been identified for the current flu season, and it contains three times the antigen of standard-dose inactivated influenza vaccines.

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. And the annual influenza vaccination is recommended for all persons aged six months and older who do not have contraindications. 'Providers should be aware of the potential for increased reactogenicity with coadministration and consult the CDC for updated guidance as more information becomes available. If coadministered, COVID-19 vaccines and vaccines that might be more likely to cause a local reaction (e.g., aIIV4 or HD-IIV4) should be administered in different limbs, if possible.'

'No data are currently available concerning coadministration of currently Authorized COVID-19 vaccines and influenza vaccines,' stated Lisa Grohskopf, M.D., MPH, CDC's ACIP vaccine committee presentation (slide #14) on June 24, 2021.

FluBlok Quadrivalent Dosage

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

FluBlok Quadrivalent News 2020 - 2022

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

May 4, 2022 - Flu News Europe reported that during week 16, 11 of 40 countries across the Region reported widespread influenza activity. Both influenza type A and type B viruses were detected, with A(H3) viruses being dominant across all monitoring systems.

April 8, 2022 - The CDC reported that the cumulative hospitalization rate in the FluSurv-NET system is higher than the rate for the entire 2020-2021 season but lower than the rate seen during the four preceding four seasons of the COVID-19 pandemic.

November 11, 2021 - The WHO's report on influenza indicated that influenza activity remains low, while RSV activity was increased in various countries.

October 7, 2021 - Respiratory Datamart in the U.K. has reported eight influenza-positive cases in week 40.  

September 11, 2021 - The US CDC reported during week 36, the percentage of patient visits for ILI remains below the national baseline.

August 13, 2021 - Nationwide, during week 31, 2.0% of patient visits reported through ILINet were due to ILI. Although increasing, the percentage of patient visits for ILI remains below the baseline of 2.6% nationally. One Region (Region 7) is at its region-specific baseline, while the remaining regions are below their baselines. Influenza virus circulation remains low; therefore, increases in ILI activity are likely due to increased circulation of other respiratory viruses.

November 18, 2020 - The European Commission has granted marketing authorization for Supemtek®, a quadrivalent (four-strain) recombinant influenza vaccine, to prevent influenza in adults 18 years and older. Supemtek is the first and only recombinant influenza vaccine now approved in the European Union.

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 need. 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 manufacture, control, quality, non-clinical and clinical evaluation.

FluBlok Quadrivalent Clinical Trials

Flublok Quadrivalent vaccine has been studied in 29 clinical trials.