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Understanding Influenza, Pandemic Flu

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Brief Description:

Influenza, or flu, is a respiratory infection caused by several flu viruses. Pandemic flu refers to particularly virulent strains of flu that spread rapidly from person to person to create a world-wide epidemic (pandemic).


Balintfy: The flu, like the common cold, is a respiratory infection caused by viruses. But the flu differs in several ways from the common cold. For example, people with colds rarely get fevers or headaches or suffer from the extreme exhaustion that flu viruses cause. The most familiar aspect of the flu is the way it can "knock you off your feet" as it sweeps through entire communities.

Fauci: There are two reasons to be concerned about the flu.

Balintfy: Dr. Anthony Fauci is the director of the National Institute of Allergy and Infectious Diseases. He explains that one concern is that seasonal flu — a flu outbreak that occurs yearly — is itself a serious disease, killing more than a quarter of a million people worldwide.

Fauci: There’s also the threat of having what we call a pandemic flu.

Balintfy: Pandemic flu refers to particularly virulent strains of flu that spread rapidly from person to person to create a world-wide epidemic.

Fauci: One of the best weapons against influenza is a vaccine that induces what we call neutralizing antibody. And a neutralizing antibody is an antibody that can actually block the virus in question. The trouble with the induction of neutralizing antibodies with flu is that they are usually directed against a component or portion of the virus that changes readily from strain to strain, and certainly changes when you have a pandemic virus or a pandemic strain. That’s the reason why each year we have to revaccinate people so that you can keep up with the drifting of the strains by mutations that occur.

Balintfy: The influenza virus is one of the most changeable of viruses with genes known for "drifting and shifting." These genetic changes may be small and continuous or large and abrupt. Dr. Fauci points to a universal vaccine as a research target.

Fauci: The universal vaccine is one that you can give to an individual that would protect against an entire menu, as it were, of different strains of influenza.

Balintfy: For more information about flu viruses and the latest research on influenza, visit This is Joe Balintfy, National Institutes of Health, Bethesda, Maryland.

Date: 4/29/2009

Reporter: Joe Balintfy

Sound Bite: Dr. Anthony Fauci

Topic: influenza, flu, pandemic, virus


This page was last reviewed on May 1, 2009 .
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