NHS Choices

Flu vaccine side effects

Any side effects after a flu vaccine are usually very mild and only last for a day or so. The most common side effects are a sore arm, mild fever or slight muscle aches. aTIV the vaccine for best protection in older people is more likely to cause a sore arm

The flu vaccine cannot cause flu.

If you have a sore arm after the vaccination, try these tips to ease it:

  • continue to move your arm regularly
  • use a heat pack or warm compress on the area
  • use an ice pack on the area if it becomes hot and sore – do not apply ice directly to your skin: wrap it in a towel first
  • take a painkiller, such as paracetamol or ibuprofen – do not give aspirin to children under 16

If you have what you think is flu after vaccination, it may be that you have caught a flu-like illness that isn't really flu, or you may have caught flu before your flu vaccination had taken effect. Protection usually starts 10-14 days after the flu vaccination.

Allergic reactions to a flu vaccine

Serious allergic reactions (anaphylaxis) to flu vaccines are very rare. Healthcare staff giving vaccinations are fully trained to deal with anaphylaxis, and with prompt treatment, individuals make a quick and complete recovery.

Contact your GP surgery or community pharmacist if you experience severe side effects that are not improving over time.


Click here to see all vaccination leaflets.

Last Updated: 01/04/2017 09:00:00