The BCG (Bacillus Calmette - Guerin) vaccine gives protection against TB disease. The BCG vaccination programme has changed in the Isle of Man and in the UK in recent years.
Until 2005 there was a universal policy of vaccinating all children in school. The change to a selective policy was brought about because of the change in the patterns of TB in the UK. The lower the risks of TB infection, the lower are the benefits of BCG.
The criterion for significant risk of exposure to TB is having prolonged contact with individuals in communities with 40 cases of TB per 100,000 population. The Isle of Man has approximately 8.5 cases per 100,000 population and therefore the risk of exposure to TB disease is well below this threshold.
BCG vaccine contains live organisms derived from Mycobacterium bovis that have been attenuated (modified). BCG vaccine does not contain thiomersal or any other preservatives.
BCG is very efficacious against TB meningitis in babies and young children, but its efficacy against pulmonary tuberculosis appears to be variable.
In some individuals it is important to check their previous exposure to TB disease before administering the vaccine. If they have already been exposed to TB disease, they may not benefit from the vaccination. The test done to establish this is called the Mantoux test which shows sensitivity to the bacteria causing TB disease. Many people believe that the Mantoux test demonstrates a person’s immunity to TB - this is a myth.
The BCG vaccine is administered just under the skin’s surface (intradermal). This is a different technique to the administration of other childhood immunisations which is intra muscular - into the muscle.
Protection to routine childhood immunisations is usually achieved within 2 weeks. However, the protection against TB afforded by the BCG vaccine takes up to 6 weeks. The nurses or doctors who administer the vaccine give specific advice about the care of the vaccination site.
For further help and advice on Tuberculosis please contact Public Health on +44 1624 642615 or +44 1624 642657.