The influenza virus mutates so fast that even if the vaccine is updated every year, there is no guarantee that the vaccination will cover all the seasonal epidemic. Influenza vaccination does not guarantee a 100% protection against influenza, and may also lead to side effects such as low fever in vaccinated people. 
Influenza vaccination can reduce the risk of serious complications from influenza in children, patients with chronic diseases and other high-risk groups
 there is no need to be vaccinated against influenza.