Vaccine Info

Flublok Quadrivalent Influenza Vaccine

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 there since 2016 and has been distributed to over 9 million people. The FDA considers the vaccine safe and acceptable for use.

For 2020-2021, cell- or recombinant-based vaccines are recommended to contain:

  • A/Hawaii/70/2019 (H1N1)pdm09-like virus (updated)
  • A/Hong Kong/45/2019 (H3N2)-like virus (updated)
  • B/Washington/02/2019 (B/Victoria lineage)-like virus (updated)
  • B/Phuket/3073/2013-like (Yamagata lineage) 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

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 on the basis of a review of the manufacture, control, quality, non-clinical and clinical evaluation.