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Flublok Seasonal Influenza (Flu) Vaccine

Questions & Answers

On January 16, 2013, the U.S. Food and Drug Administration (FDA) announced its approval of Flublok, an influenza vaccine made by Protein Sciences Corporation, for the prevention of seasonal influenza in people 18 years and older.

What is Flublok?

Flublok® is a trivalent influenza vaccine that has been FDA approved for use in adults 18 years and older.

How does this vaccine differ from the other approved flu vaccines?

Flublok is produced differently and has a slightly shorter shelf life than most influenza vaccines.

  • Flublok does not use the influenza virus or chicken eggs in its manufacturing process. See How Influenza (Flu) Vaccines Are Made for more information.
  • Flublok has a slightly shorter shelf life than most other currently available injectable influenza vaccines; it expires 9 months from the production date. Health care providers should check the expiration date before administering Flublok.

What are the possible benefits of Flublok vaccine?

Flublok’s manufacturing process has the potential for faster startup of vaccine manufacturing, which can be useful in the event of a pandemic or vaccine supply shortage, mainly because it is not dependent on an egg supply or limited by the selection of vaccine viruses that are adapted for growth in eggs. Also, this vaccine is suitable for vaccinating people with egg allergies because it is not made using eggs.

Who can get Flublok vaccine?

Flublok is approved for use in people 18 years and older.

Who should not get Flublok vaccine?

People who are not within the FDA-approved age range (those younger than 18 years) and people with known severe allergic reactions to any component of the vaccine should not get Flublok.

Is this vaccine safe?

Clinical studies show that Flublok is safe and effective for use in people 18 years and older. Flublok meets FDA’s standards for influenza vaccines.

Are there any side effects that could occur?

The most common side effects reported after receipt of FluBlok were similar to those reported for other flu shots and include pain at the injection site, headache, fatigue, and muscle aches.

For more information see the FluBlok package insert.

People who have ever had a severe allergic reaction to eggs can get recombinant flu vaccine if they are 18 years and older or they should get the regular flu shot (IIV) given by a medical doctor with experience in management of severe allergic conditions. People who have had a mild reaction to egg—that is, one which only involved hives—may get a flu shot with additional safety measures. Recombinant flu vaccines also are an option for people if they are 18 years and older and they do not have any contraindications to that vaccine. Make sure your doctor or health care professional knows about any allergic reactions. Most, but not all, types of flu vaccine contain a small amount of egg.


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