Side effects of the flu vaccine

As with all medicines, side effects of the flu vaccine are possible, but usually mild.

These potential side effects are much less serious than developing flu or complications associated with flu.

Common side effects

Common side effects of the flu vaccine may include:

  • tenderness, swelling and/or redness at the injection site
  • headache
  • muscle aches
  • fever (temperature 38°C or above)
  • feeling generally unwell

Non-urgent advice: When to get help

If you are concerned about yourself or anyone else in your household who is unwell following a vaccination, phone NHS24 on 111.

Flu vaccination, fever and coronavirus

It is quite common to develop a fever (temperature 38°C or above) after a vaccination. This would normally happen within 48 hours of the vaccination and usually goes away within 48 hours.

You do not need to self-isolate or book a coronavirus test unless you have other coronavirus symptoms or if you have been advised to by:

  • NHS Test and Protect
  • your Occupational Health team
  • a Public Health Protection team

If the fever started 48 hours after the vaccination or continues beyond 48 hours from the time of the vaccination, you should self-isolate and book a test.

For more information about the latest advice visit our coronavirus pages or phone 0800 030 8013.

Further information about vaccine side effects

More information on the possible side effects of the flu vaccine is available in the Patient Information Leaflets:

Where can I report suspected side effects?

You can report suspected side effects of vaccines and medicines through the Yellow Card Scheme.

This can be done by:

  • visiting the Yellow Card Scheme website
  • phoning the free Yellow Card hotline 0800 731 6789 (9.00am to 5.00pm, Monday to Friday)

If you’re unsure about anything or have any questions about the flu vaccine, speak to a health professional, such as your immunisation nurse, practice nurse or GP.