Possible side effects of the flu vaccine

The flu vaccine can have side effects for certain patients. Here are some of the most common side effects:

• Soreness at the site of the injection is common – this will only last a day or two.
• A fever and muscle aches may start within 12 hours and again will only last a day or two. This is very uncommon in adults, but not uncommon in children and the elderly.

If you have these symptoms it does not mean that you have caught ‘flu from the vaccine, but that your immune system is responding to the vaccine. If you get these symptoms more than a day after you received the vaccine, or if they last longer than two days, then it is almost certainly an illness not related to the vaccine.

Reviewed (2006) by Dr Jane Yeats MBChB, BSc(Med)(Hons)Biochem, FCPathSA(Virology).