Choose Flublok,
a higher-dose flu vaccine.
THE FLU IS MORE DANGEROUS THAN YOU MAY THINK.
On this page:
- 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
- Flublok contains 3x more antigen than a regular flu shot
- Compared to a standard dose flu shot, a clinical study showed Flublok provided 30% more flu protection. Another study showed that compared to standard dose flu shots, Flublok cut down hospitalizations by 31%
- Flublok is the only flu vaccine made with recombinant protein-based technology
Flublok: 3x more antigen
Contains 3x more antigen than a regular flu shot
The better
protection of Flublok
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)*
Flublok: the only flu shot of its kind
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
Flublok: Lower rate of hospitalization
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‡
Flublok was well tolerated
In a patient reported study of 439 adults aged 18 to 64 years, 91% of patients found the local reactions experienced after receiving Flublok to be very or totally tolerable and acceptable. When asked, ~97% of these patients said they would be willing to receive Flublok again next year.||
Flublok is free of thimerosal, aluminum, formaldehyde, and latex.
*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.
||"Yes, definitely" or "Yes, probably."
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 study results
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
individuals
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 June 10, 2026. 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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