Influenza also known as the flu is a highly contagious viral infection of the respiratory passages causing fever, severe aching, and catarrh, and often occurring in epidemics. Luckily it can be easily avoided by a vaccine called the flu shot. Influenza is the most frequent cause of death from a vaccine-preventable disease in the United States. In a study of influenza seasons from 1976–1977 through 2006–2007, the estimated number of annual influenza-associated deaths from respiratory and circulatory causes ranged from a low of 3,349 (1985–1986 season) to a high of 48,614 (2003–2004 season) there was an average of 23,607 deaths because of influenza. Without an exact number, most if not all, people have had the flu or common cold that's why doctors really express the need for the vaccine and why they make it so easy to have access to the vaccine, for example you can go get it done at a doctors office, your nearest CVS or Walgreen's. The flu may effect many things with your body but it mainly effects your nose, throat and lungs, people often have runny noses, sore throats, a cough and a fever. It makes you physically weak and not able to do much except for sit on the couch and be miserable. Luckily there is a vaccine but how does it work? After the shot is injected antibodies fight against the infection making it a two week process because the B cells respond and work with the Influenza virus. The most common way that flu vaccines are made is using an egg-based manufacturing process that has been used for more than 70 years. Egg-based vaccine manufacturing is used to make both inactivated (killed) vaccine (usually called the “flu shot”) and live attenuated (weakened) vaccine. Overall most people will have the flu in their life so it is very important to get vaccinated even I get a flu shot every once in a while and I am so glad I have.