Introduction In recent years, influenza vaccines have received more and more attention from people, but some doctors do not recommend taking influenza vaccines. So why? Next we will discuss this issue from two aspects: the effectiveness and safety of influenza vaccines. In terms of effectiveness, first, let’s take a look at the effectiveness of the flu vaccine. There are many types of influenza vaccines, and each year\’s vaccine needs to be based on the mutation of the influenza virus that year.