Influenza? Who need this vaccine?

What is Influenza?
The flu (or common flu) is a viral infection that is spread from person to person in secretions of the nose and lungs, for example when sneezing. Medically, the common flu is referred to as influenza. Flu is a respiratory infection, that is, an infection that develops primarily in the lungs. Influenza usually causes higher fever, more malaise, and severe body aches than other respiratory infections. 

Types Of Influenza
Influenza viruses are divided scientifically into three types, designated A, B, and C. Influenza types A and B are responsible for epidemics of respiratory illness that occur almost every winter. Influenza type C usually causes either a very mild respiratory illness or no symptoms at all; it does not cause epidemics and does not have the severe public-health impact of influenza types A and B. 

The Vaccination
Flu vaccine is an inactivated vaccine, meaning that it contains killed influenza virus. The killed influenza virus is injected into muscles or skin and stimulates the immune system to produce an immune response (antibodies) to the influenza virus.
Influenza vaccination is safe for anyone 6 months of age and older. It protects you and those around you from the flu and its complications. Babies and children 6 months to 9 years of age who have never had a flu shot will need 2 doses of the vaccine, given at least 4 weeks apart. Children who had one or more doses of the regular seasonal flu shot in the past will only need one dose per year.