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Flublok, manufactured by Protein Sciences, is a trivalent flu vaccine that was first approved by the Food and Drug Administration (FDA) in 2013. The FDA approved a quadrivalent form of the vaccine (Flublok Quadrivalent) in October 2016.

What Makes Flublok Different from Other Flu Vaccine Brands?

Flublok and Flublok Quadrivalent are the first flu vaccines to be made using what is known as “recombinant DNA technology.” Rather than growing an entire flu virus, the manufacturer isolates special proteins found on the virus, and then mixes them with other proteins to create a substance that can be transformed into a purified influenza vaccine.

This technique results in several notable outcomes. The first is that Flublok does not contain egg protein – one of the primary causes of severe allergic reactions among certain individuals who receive the flu vaccine.  In addition, because the Flublok vaccines contain three times the active ingredient of other flu vaccinations, Flublok vaccines may be a better option for individuals having weakened immune systems. According to a study published by Protein Sciences, individuals immunized with Flublok Quadrivalent are 40 percent less likely to be diagnosed with influenza than those who receive Fluarix Quadrivalent.

Who Can Receive Flublok and Flublok Quadrivalent Injections?

Currently, Flublok and Flublok Quadrivalent are only approved for immunization of individuals 18 years of age and older. While the Flublok vaccines do not contain egg protein, the Centers for Disease Control and Prevention (CDC) still caution that individuals with allergies should consult their physicians before being vaccinated with Flublok or Flublok Quadrivalent.

What Are the Most Common Side Effects Associated with Flublok?

The CDC lists a number of common side effects associated with the Flublok influenza vaccines. These include:

  • Pain at the injection site
  • Headache
  • Fatigue
  • Muscle aches

According to the FDA, tenderness is the most common side effect associated with Flublok (48 percent of adults age 18 through 49), followed by pain at the injection site (37 percent).

How are Flublok and Flublok Quadrivalent Administered?

Flublok and Flublok Quadrivalent are administered via intramuscular injection, typically in the shoulder. Both require a single 0.5 milliliter dose, and like all flu vaccines, should be re-administered on an annual basis.

Is Flublok Safe for Women Who Are Pregnant?

According to the FDA, the pregnancy-related effects of Flublok and Flublok Quadrivalent are still under investigation. Women who are pregnant and interested in being immunized with Flublok or Flublok Quadrivalent should consult their doctors.

Could My Shoulder Pain Be the Result of a Flublok or Flublok Quadrivalent Vaccination?

Possibly. If you experience shoulder pain or other symptoms following administration of the Flublok or other flu vaccine, these could be signs of a vaccine-related shoulder injury. The most common shoulder injuries linked to flu shots are shoulder injury related to vaccine administration (SIRVA). These injuries result from errors that occur during the vaccination process, not from adverse reactions to specific vaccines or vaccine ingredients.

If you have been diagnosed with SIRVA following a Flublok or Flublok Quadrivalent injection, the Center for Vaccine Shoulder Pain Recovery may be able to help you secure financial compensation from the government. To learn more, schedule a free consultation today.

Schedule a Free Consultation about Your Flu Vaccine Shoulder Injury

Located in Washington D.C., the Center for Vaccine Shoulder Pain Recovery provides no-cost, nationwide legal representation for SIRVA claims under the National Vaccine Injury Compensation Program (VICP). If you have been diagnosed with a vaccine-related shoulder injury and would like to learn more about your rights under the VICP, call us at (844) 789-2047 or request a free consultation online today.

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The Center for Vaccine Shoulder Pain Recovery


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