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6-in-1 vaccine side effects

The 6-in-1 vaccine is very safe but, as with all medicines, a few babies will have side effects. In general, side effects are mild and short-lived. Most babies won't have any problems at all.

Common reactions to the 6-in-1 vaccine

The side effects that are most often reported after the 6-in-1 vaccine, in up to 1 in 10 babies, are:

  • pain, redness and swelling at the injection site
  • fever
  • vomiting
  • abnormal crying
  • irritability
  • loss of appetite

Rare side effects after the 6-in-1 vaccine

Other possible, but much rarer, side effects – reported in fewer than 1 in 10,000 babies – include:

  • high fever (above 39.5°C)
  • fits or seizures

Allergic reaction to the 6-in-1 vaccine 

Very rarely, a baby will have a severe allergic reaction (anaphylaxis) after the 6-in-1 vaccine. This happens in fewer than 1 in 100,000 cases, and it can happen with any vaccine.

Anaphylaxis is a serious medical condition, but all vaccination staff are trained to deal with anaphylactic reactions on the spot, and babies recover completely with prompt treatment.

What to do if your baby gets a fever

If your child develops a fever after their 6-in-1 vaccination, keep them cool by:

  • making sure they don't have too many layers of clothes or blankets on
  • giving them cool drinks

You could also give them infant paracetamol to reduce their fever.

Call the doctor immediately if, at any time, your baby's temperature gets higher than 39°C.

What to do if your baby has a serious side effect

See your doctor if your baby is very unwell or you're concerned in any way about their health following a vaccination.

If your baby has a fit or any serious medical problem once they're home after their vaccination, call your GP or an ambulance immediately.

Seizures can look very alarming, but babies usually recover from them quickly.

If you are concerned about how your baby reacted to a previous dose of the 6-in-1 vaccine, talk to your GP, nurse or health visitor.

Monitoring safety of the 6-in-1 vaccine

In the UK, the safety of vaccines is monitored through the Yellow Card Scheme by the Medicines and Healthcare products Regulatory Agency (MHRA) and the Commission on Human Medicines.

Most reactions to the 6-in-1 vaccines reported through the Yellow Card Scheme have been minor, such as a rash, fever, vomiting and redness, and swelling at the site of the injection.

Find out how to report a vaccine side effect.

Last Updated: 17/02/2022 16:00:16
The information on this page has been adapted by NHS Wales from original content supplied by NHS UK NHS website