Does the vaccine have any side effects?

Millions of doses of the vaccine have been used and it has a very good safety record.  

Like all medicines, vaccines can cause side effects. Most of these are mild and short term, and not everyone gets them.  

Vaccine side effects are minor compared to getting seriously ill from the diseases. 

The most common side effects include:  

• a sore leg or arm where the injection was given 
• a small lump where the needle was put in (this is normal and may last some weeks and does not need any treatment) 
• a raised temperature (fever) over 38°C 
• feeling unsettled, and 
• loss of appetite. 

If your child has a raised temperature and seems unwell, keep them cool by:  

• making sure they don’t have too many layers of clothes or blankets on, and  
• giving them plenty of cool drinks.  

Very rare side effects from the vaccine include:  

• allergic reactions, such as swelling of the face, lips, tongue or throat, hives (a raised, itchy rash), difficulty breathing or swallowing, and feeling dizzy. 

These symptoms may be a sign of a serious allergic reaction and usually happen within 15 minutes of being vaccinated. Call 999 straight away if your child has had the vaccine and has any of these symptoms. 

You can find reports of all side effects in the patient information leaflet for the vaccine. For more information on side effects, go to:  

• Infanrix hexa (emc - medicines.org.uk) (external site)  
• Vaxelis (www.gov.uk) (external site)

If your child’s symptoms get worse or if you are concerned, contact NHS 111 Wales by calling 111 or your GP surgery. Calls to NHS 111 Wales are free from landlines and mobile phones. 

You should report suspected side effects of vaccines and medicines online at mhra.gov.uk/yellowcard (external site), by downloading the Yellow Card app, or by calling 0800 731 6789 (Monday to Friday, 9am to 5pm).