Influenza(flu) affects millions of individuals each year. As the most commonly circulating flu strains vary a new seasonal immunization is developed annually. Receiving the seasonal flu vaccine annually is the most effective way to protect oneself against the flu. The viruses used in the vaccine are based on extensive surveillance and research on which strains will be the most prominent during the upcoming flu season.   Seasonal flu vaccines protect against influenza A and influenza B, and other types of flu shots provide other types of protection. Following the flu shot, it takes two weeks for antibodies to develop in the body to provide protection. During the two-week period, individuals should avoid touching their mouth or nose, practice good hygiene, and avoid crowds in communities in which the flu is circulating.   The body’s immunity to the flu decreases over time for patients who have received the vaccine or not for that reason and due to varying strains, a flu vaccine may not protect an individual from one flu season to the next. For that reason, it is advisable to receive the seasonal flu vaccine annually for maximum protection.