About the BCG vaccination and Mantoux test (to protect against TB)

The BCG vaccination was offered as a routine part of the NHS immunisation programme for all children up until 2005, when the programme ended. However, we are able to offer the vaccination for occupational health purposes and for individuals travelling for more than three months to parts of the world where TB is more than 40/100,000. We also hold a clinic once a month for parents who are concerned about rising infection rates within the UK and request the vaccine for their children who have not previously been vaccinated against TB.

What is the Mantoux test?

Before having the BCG, you must have the Mantoux test (with the exception of most children less than six years of age, however, the nurse will advise). This is a test to check whether the person has ever been in contact with the bacteria (germs) that cause tuberculosis. The test involves injecting a small amount of tuberculin into the skin on your arm. If a red lump of more than six millimetres (6 mm) in diameter develops, the test is positive and you should not be given the BCG vaccination. Normally no further action is required, but if the reaction is 15mm or more, referral to a specialist is indicated. If no lump develops, then this suggests that the individual has not been exposed to TB and therefore should proceed with the BCG vaccination.

The BCG vaccination

The BCG vaccination is given as a single injection to the upper left arm. After the vaccination, a small red spot usually develops within two to six weeks. After a few weeks, the spot usually becomes weepy with crusting and slight bruising. This will eventually heal to form a round flat scar.