BCG Immunisation - Risks

How is BCG immunisation given?

The BCG jab is given as a single injection into the skin of the outside of the upper arm, usually the left arm.

For at least three months following BCG immunisation, no other immunisation should be injected into the arm which received the BCG jab.

Who should not be given a BCG immunisation?

The BCG immunisation should not be given to:

  • Those who have already had a BCG immunisation.
  • Those with a past history of tuberculosis (TB) infection.
  • Those with a strong reaction to Mantoux skin testing.
  • Those who have had a confirmed severe allergic reaction to any substance in the BCG immunisation.
  • Newborn babies who live in a house where someone has definite or suspected TB infection.
  • People who have reduced body defences (immune system) - for example, those using steroid tablets, those with AIDS or those who have cancer.

BCG immunisation can be given if you have a minor illness without a high temperature (fever) and are not feeling unwell. If you feel very unwell, the BCG jab should be delayed until you have recovered. BCG immunisation can be given during pregnancy and when breast-feeding. However, it is usually delayed during pregnancy, especially during early pregnancy.

Can BCG immunisation cause any side-effects?

BCG immunisation is very safe. Occasionally reactions can occur at the injection site - for example, infection and scarring. Allergy reactions can occur but are also uncommon.

Other uncommon side-effects can include headache, swelling of lymph glands in the armpit and an ulcer at the site of the injection.

It is possible for BCG immunisation to cause a TB infection in the body but this is very rare.

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Dr Laurence Knott
Peer Reviewer:
Dr Adrian Bonsall
Document ID:
28847 (v2)
Last Checked:
05 July 2017
Next Review:
04 July 2020

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Patient Platform Limited has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.