No, it is a myth that the flu vaccine causes the flu.
Flu vaccinations cannot cause the flu because injected flu vaccines contain inactivated (killed) viruses rather than live viruses, meaning they cannot cause infection. The nasal spray vaccine given to children, however, does contain a specially modified (“cold-adapted”) live virus, although deemed ‘live’ it cannot survive at normal body temperature and is therefore also incapable of causing infection.
The myth probably arose due to people experiencing side effects of the vaccination. Side effects are usually mild and include soreness, redness, and/or swelling where the shot was given, headache (low grade), fever, nausea, muscle aches, and fatigue but only last a day or two. But you can see that some side effects of vaccination are also symptoms of flu – which is where the confusion may come from. While some people may feel slightly unwell after having the flu jab, the simple fact is it doesn’t give you the flu.