Side effects of the flu jab

Lots of people don’t experience any side effects when they have a flu vaccine. The most common side effect is a sore arm.

Last updated: 6 April 2022

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Common side effects of the flu vaccine

Some people don't experience any side effects after a flu jab. But the most common reactions are:

  • a sore arm, or pain, itching, or redness at the injection site (1 in 3 adults)
  • aches and pains (1 in 10 adults)
  • feeling feverish, tired, or unwell

These are normal responses to the vaccine.

You may be asked to wait 15 to 20 minutes after your vaccination so that treatment can be given quickly if a very rare, severe allergic reaction occurs. Many people aged 13 years and older will only need to wait 5 minutes. Children under 13 years will need to wait 20 minutes.

Allergic responses are extremely rare. 


Taking paracetamol after a flu jab 

Paracetamol is not routinely recommended for use to control fever after the flu jab is given. However, it can be administered if the side effects are causing too much discomfort 

There’s some evidence that the immune response can be affected by paracetamol, but there’s no evidence that this causes people to be less well protected from disease. 


The vaccine can’t give you flu 

You can’t get the flu from the flu jab. The flu vaccine doesn’t contain any live viruses so it can’t give you flu. 

It takes up to two weeks for the body to develop protection against flu. If you’ve been infected with the flu before or soon after having the vaccine, you can still get the flu. If these symptoms continue or get worse, talk to your healthcare provider or call Healthline on 0800 611 116 


Medsafe adverse reaction (side effects) reports 

Medsafe publishes detailed reports of the side effects reported in New Zealand after a person has had a flu vaccine.  

Influenza Vaccine Adverse Drug Reaction Reporting Statistics – Medsafe 

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