Why is it important to get a flu vaccine every year?
It is recommended to get a flu vaccine every year because flu viruses mutate. The composition of a flu vaccine is reviewed annually and updated as needed so that it would effectively protect the population against flu viruses that change every year. It has been found that the body's resistance to influenza viruses decreases over the course of the year, but the vaccine provides protection against infection for the entire season. Therefore, it is important to get vaccinated every year, even if the composition of the flu vaccine has not changed.