Vaccine Info

Flublok Quadrivalent Influenza Vaccine

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Last reviewed
June 12, 2021

FluBlok Quadrivalent Vaccine Description

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 has been 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.

For 2021-2022, U.S. Cell- or recombinant vaccines are recommended to contain the following:

A/Wisconsin/588/2019 (H1N1)pdm09-like virus

A/Cambodia/e0826360/2020 (H3N2)-like virus

B/Washington/02/2019 (B/Victoria lineage)-like virus

B/Phuket/3073/2013-like (B/Yamagata)-like virus 

FluBlok Quadrivalent Vaccine Indication

Flublok Quadrivalent is a vaccine given to people 18 through 64 years of age. It consists of the 4 influenza strains that have been identified for the current flu season.

FluBlok Quadrivalent Vaccine Dosage

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

FluBlok Quadrivalent Vaccine News

November 18, 2020 - The European Commission has granted a marketing authorization for Supemtek®, a quadrivalent (four-strain) recombinant influenza vaccine, to prevent influenza in adults aged 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 UK 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 based in part 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 Vaccine Clinical Trials

Flublok Quadrivalent Vaccine has been studied in 29 clinical trials.