Flu Terms Defined

Seasonal (or common) flu is a very contagious, respiratory illness that can be transmitted from person to person by coughing and sneezing. Most people have some immunity, and a vaccine is available.

Avian (or bird) flu is an infection caused by avian (bird) influenza (flu) viruses. These influenza viruses occur naturally among birds. Wild birds worldwide carry the viruses in their intestines, but usually do not get sick from them. However, avian influenza is very contagious among birds and can make some domesticated birds, including chickens, ducks, and turkeys, very sick and kill them.  It can be transmitted from birds to humans. There is no human immunity and no vaccine is available.

Pandemic flu occurs when a new influenza virus emerges for which people have little or no immunity, and for which there is no vaccine. The disease spreads easily from person-to-person, causes serious illness, and can sweep across the country and around the world in a very short time.