WHAT IS THE FLU: The flu is caused by the influenza virus, which targets the respiratory tract. The viruses bind to the surface of cells, then releases its genetic information into the cell's nucleus to replicate itself. When the cell dies, those copies are released into the body, infecting other cells. Flu symptoms are unpleasant, but not life-threatening by themselves. However, the flu weakens the immune system, making the body vulnerable to more serious infections, such as pneumonia. Because the flu is caused by a virus -- as opposed to bacteria -- antibiotics are not an effective treatment. Both the flu and the common cold are best treated by bed rest, consuming lots of fluids, and taking over-the-counter medication to ease symptoms until the virus runs its course.
DOGS GET THE FLU: The H3N8 virus is believed to have moved from horses to dogs a few years ago. For about 80% of canines it brings 2 or 3 weeks of coughs, runny noses and fevers, but for the unlucky others, it can cause pneumonia and other complications. Roughly 5 to 8% die from it. Researchers developed a vaccine to prevent the disease and are using it now with dogs that frequently socialize with other dogs.
HOW VACCINES WORK: There are three basic strains of the flu virus: A, B and C. A is the most common and most severe strain. The flu vaccine works by triggering the body's immune system response. The body recognizes the vaccine as a foreign invader and produces antibodies to it. However, flu strains differ from year to year, so different vaccines are needed each year. Flu vaccines are made by incubating the three strains of the virus expected to strike in a given year (they are injected into millions of chicken eggs to multiply), then extracted and packaged. It is a labor-intensive and time-consuming technique that is much the same as when it was first invented in the 18th century.
The American Association of Pharmaceutical Scientists contributed to the information contained in the TV portion of this report.