Vaccine Info

Flublok Quadrivalent Influenza Vaccine

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Last reviewed
November 11, 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, and 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 and COVID-19 Vaccines

The US Centers for Disease Control and Prevention (CDC) previously 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 6 months and older who do not have contraindications. 'Providers should be aware of the potential for increased reactogenicity with coadministration and should 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 Vaccine Dosage

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

Supemtek EU Influenza Vaccine

FluBlok quadrivalent is marketed in the EU as Supemtek. It was authorized by the European Commission 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 News

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 UK has reported 8 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 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.