Vaccines, Blood & Biologics

Questions & Answers on Inactivated Influenza Vaccines for Use in 2003-2004

Is any influenza vaccine being recalled?

No. There is, to date, no recall of any influenza vaccine that has been produced for use in the 2003-2004 influenza season.

Why are there rumors that influenza vaccine is being recalled?

Two individuals at a single medical center had clinical symptoms suggesting allergic reaction after influenza vaccine administration; the first individual developed severe symptoms suggesting allergy immediately after administration of the influenza vaccine, and the second person developed symptoms within a day of receiving the influenza vaccine, but it is unclear whether a severe allergic reaction occurred. Both of these individuals had received vaccine from the same lot of vaccine. The medical center prudently questioned whether a pattern of adverse reactions was developing for this lot of vaccine. Further review of all information indicates that one of the individuals had underlying lung disease and was subsequently diagnosed with pneumonia. Similar adverse reactions have not been reported in other locations where the same lot of vaccine has been in use. Review of manufacturing data indicates that the lot of vaccine meets all manufacturing requirements and release specifications and suggests no irregularities. Investigation of these cases is continuing.

What could cause FDA or a manufacturer to initiate a recall of a product?

A recall could be initiated if, among other reasons, vaccine presented a substantial hazard to the public health, such as an unexpected and otherwise unexplained number or severity of adverse reactions.

Are inactivated influenza vaccines produced for 2003-2004 season safe?

Yes. When inactivated influenza vaccines are used according to instructions given in the package insert, they are safe. Before they are released for use, influenza vaccines undergo extensive evaluation, including tests to ensure that the influenza viruses have been properly inactivated, that the active and inactive ingredients are present in the correct quantities, and that the vaccines are sterile. Influenza vaccines are highly effective and prevent thousands of deaths each year.

What kinds of adverse events are most common after administration of inactivated influenza vaccine?

Most adverse reactions to inactivated influenza vaccine are related to the body's response to the vaccine components at the site of injection. Most commonly, there is inflammation at the injection site, which may result in redness, swelling or pain. Less frequently, more general reactions occur including fever, malaise (a vague feeling of being ill), and muscle aches.

Are serious immediate allergic reactions to inactivated influenza vaccines common?

No, but a few such reactions are reported with inactivated influenza vaccine use every year. Serious immediate reactions can occur within a few minutes to a few hours in people who likely have allergies to components of the vaccines, which may contain very small amounts of residual egg protein. Immediate allergic reactions can appear in a mild form as itching and hives; however, in the severest form, allergic reactions can result in difficulty breathing, loss of blood pressure, and, while prompt medical treatment is usually effective, even death.

What can be done to prevent or treat severe immediate allergic reactions?

First, the vaccine is contraindicated for people with a history of hypersensitivity to eggs or egg products or other components of influenza vaccines. Additionally, as with all vaccines, it is prudent that recipients remain under observation for the first 15-30 minutes after the vaccine is injected to detect and treat any rare, serious allergic reactions and that medications, such as epinephrine and benadryl, used to treat such reactions, be available for immediate use.

How do I report adverse reactions?

Reports on adverse reaction to influenza vaccine or any other vaccine should be sent to the Vaccine Adverse Reporting System (VAERS) which is jointly operated and reviewed by FDA and CDC. VAERS can be reached at 1-800-822-7967 or on the internet at

What are the benefits of influenza vaccine?

Influenza (flu) is a highly infectious disease of the lungs, and it can lead to pneumonia. Each year about 114,000 people in the U.S. are hospitalized and about 36,000 people die because of influenza. Most who die are 65 years and older. But children younger than 2 years old are as likely as those over 65 to have to go to the hospital because of influenza. The influenza vaccine is highly effective in preventing disease and thus saving lives.

Page Last Updated: 01/21/2009
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