Can I get the flu from receiving the flu shot?

Short answer: No — you cannot get the flu from the flu shot.

Not possible. Zero percent.

✅ Why you can’t get the flu from the flu shot

The flu shot contains inactivated (killed) virus, which means:

It cannot infect you

It cannot multiply in your body

It cannot cause the influenza illness

So medically, the flu shot cannot give you the flu.

✅ Then why do some people feel sick afterward?

A few normal, harmless reactions can happen as your immune system responds:

1. Mild fever

Your immune system becomes active → leads to a low-grade fever in some people.

2. Fatigue or body aches

This is a side effect, not the flu itself.

3. Sore arm

Very common due to the immune response at the injection site.

4. You were already exposed before the shot

If someone gets sick right after the vaccine, it’s often because:

They were exposed to the virus a few days before the shot

They caught a different virus (cold, RSV, COVID)

It takes 2 weeks for the flu shot to give full protection

❗ Important note

The nasal spray flu vaccine (FluMist) does contain a live-attenuated virus, but it’s weakened so much that it also cannot cause actual influenza. It may cause:

Runny nose

Cough

Mild symptoms

But not true flu illness.

✅ Bottom Line

No — the flu shot does not and cannot give you the flu.

You may feel mild symptoms as your immune system builds protection, but that’s a normal response — not an infection.