Flu Terms Defined
- Seasonal (or common) flu is a respiratory illness that can be transmitted person to person. Most people have some immunity, and a vaccine is available.
- Novel H1N1 flu is a new influenza virus causing illness in people. This new virus was first detected in the U.S. in April 2009, and has spread to many countries around the world.
- Pandemic flu is virulent human flu that causes a global outbreak, or pandemic, of serious illness. Because there is little natural immunity, the disease can spread easily from person to person.