Are you contagious when you get the flu shot?

Answer 1

No. Live vaccines are produced with careful culturing methods that ensure the virus is no longer able to do much, if any, harm.

In addition, they're given in the arm, which is not where a virus spreads from, and is not the optimal location for the viruses, so your immune system can quickly get it.

Answer 2

No, not when you have the flu shot since it is made with "dead"/inactive viruses or pieces of the virus and can't give you the flu, it will only cause your body to respond as if you had the flu (it is "tricked").

However, the nasal spray vaccine that is available in the US is made from live attenuated viruses. Attenuated simply means "weakened". They are chemically made too weak to give a person who is otherwise healthy the flu. But some people who are immuno-compromised, like those with HIV/AIDS or cancer therapy patients and those on medications to prevent organ transplant rejections, can be susceptible to the weaker forms of the virus and it may be possible, but not typical, for them to get the flu from someone who had the nasal spray for a short period immediately after the vaccination.

See also the related question below.