See the Studies Page for details on the latest real-world safety studies and effectiveness data

Flublok® is a vaccine indicated for immunization for the prevention of disease caused by influenza A and B strains represented by antigens contained in the vaccine. Flublok is given to people 9 years of age and older.

Contains 3x more antigen than a regular flu shot

In a clinical study during the 2014-2015 flu season of approximately 9,000 people, Flublok Quadrivalent was proven to provide 30% more flu protection compared to Fluarix® Quadrivalent (a standard dose vaccine) in adults 50+ (including some patients with comorbidities such as heart disease and diabetes)*

The only flu vaccine made with recombinant protein-based technology, ensuring an identical match to FDA-selected flu virus strains for manufacturing, and that does not use a live flu virus in its manufacturing process

In a real-world evidence study in approximately 15,000 people 18 years or older, those who received Flublok Quadrivalent experienced 31% fewer flu-related hospitalizations than those who received a range of cell- and egg-based regular flu shots

*The efficacies of the trivalent and quadrivalent formulations are related because both are made using the same process and have overlapping compositions.

According to the CDC, getting a flu vaccine will not give you the flu.

Study Limitations: The study population was representative of the adult population of Allegheny County, where the study was conducted, with 79% being white and 51% being female.

  The hospitals used a well-connected system that regularly updated vaccination information from the state registry, ensuring accurate records of who was vaccinated.

  If a patient’s flu shot was not recorded in the hospital system or state registry, they might have been incorrectly labeled as unvaccinated.

  The study only looked at hospitalizations, so it might have missed milder flu cases that did not require hospital care.

  Doctors might have been more likely to test unvaccinated people for flu, which could make it seem like more unvaccinated people got sick.


In adults 50 through 64 years of age who received Flublok, the most common injection site adverse reaction was pain; the most common solicited systemic adverse reactions were headache, fatigue, and muscle pain.


For additional information, please see the studies

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Schedule Flublok today.
Help protect yourself from flu.

Real results in flu protection you can count on.

Flublok is supported by one of the
largest safety studies of a flu vaccine
in pregnant women, including about 15,000
patients

Approved for over 10 years and evaluated
in the largest real-world randomized flu
effectiveness study
to date

See the data that makes a difference.

Flublok® is FREE for almost everyone.§

for Medicare
Part B

for most Medicare
Advantage plans

for most private
insurance plans

§The information above is available at CMS.gov and is current as of 5/9/2025. This information is provided for informational purposes only and is not a guarantee of coverage. The information is gathered from various resources and is subject to change.

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INDICATION

IMPORTANT SAFETY INFORMATION