The flu can lead to pneumonia and has been reported to have hospitalized 200,000 and killed 36,000 people each year.

No vaccine is 100% effective, but generally, the flu shot protects most people. Other viruses also circulate during flu season, giving you symptoms that can feel like the flu. The flu shot will not protect you against those.

Influenza, also known as "the flu", is a viral infection of the respiratory system, which includes the nose, throat, bronchial tubes and lungs. Influenza viruses are divided into three types, designated A, B, and C. Types A and B are responsible for nearly all of the influenza illness that occurs almost every winter. Infection with type C influenza usually causes either a very mild respiratory illness, or no symptoms at all. Types A and B are further subdivided into "strains".

Bird Flu" or Avian Influenza is a highly contagious viral disease that can classified as either low pathogenic (low mortality) or high pathogenic (up to 100% mortality). Low Pathogenic Avian Influenza like the common flu in humans is a common annual event in birds. High Pathogenic Avian Influenza like the H5N1 virus circulating in Asia, Europe, and Africa is less common.

Cover your mouth and nose with a tissue when coughing or sneezing or cough into your upper sleeve, not your hands. Wash your hands often with soap and warm water for 20 seconds or clean with alcohol-based hand cleaner.

Flu that spreads rapidly causing widespread epidemics around the world. Pandemic influenza occurs when a new, highly infectious and dangerous strain of the influenza virus appears. In contrast to the 'ordinary' or 'seasonal', flu outbreaks which we see every winter, flu pandemics occur infrequently ? usually every few decades. There were three in the last century. The most serious was in 1918, killing millions of people worldwide. Smaller pandemics happened in 1957 and 1968.

Anyone could get sick from pandemic flu. This is a new virus, to which no one is immune. However, about half of those who are infected can expect to have no symptoms ? called asymptomatic infection.

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. Avian (or bird) flu is caused by influenza viruses that occur naturally among wild birds. The H5N1 variant is deadly to domestic fowl and can be transmitted from birds to humans. There is no human immunity and no vaccine is available. Pandemic flu is virulent human flu that causes a global outbreak, or pandemic, of serious illness.

No. Pandemic flu is a global outbreak of human disease. It is caused by a new influenza virus that is unlike any previous flu, so people will not have any natural immunity to it. The lack of immunity means that a pandemic flu can pass readily from person to person, creating widespread illness. Currently, there is no pandemic flu circulating.