What is BCG vaccination?

BCG (Bacilli Calmette-Guerin) is a vaccine widely used for the protection against tuberculosis. However, the degree of protection is only partial and not 100%. The vaccine is considered efficacious in young children but not so in adults. It is a live attenuated vaccine given through the skin of one of the arms (either by intradermal injection or percutaneous inoculation). It should not be given to persons with impaired body immunity. Repeat doses of BCG vaccination are, in general, not indicated, as no additional benefit has been demonstrated.

The TB & Chest Service of the Department of Health provides BCG vaccination to all newborn babies in Hong Kong. Children residing in Hong Kong, who are aged below 15 and have never received BCG before, are also advised to receive the vaccine.

BCG vaccination is not required if the child has a history of proven tuberculosis or is above 15 years of age. BCG vaccination is not recommended for children with the following health conditions:

• Conditions with impaired immunity:
  • Any form of malignancy, in particular, leukaemia and lymphoma
  • Under immunosuppressive therapy such as irradiation and treatment with cytotoxic drugs or systemic steroids;
  • Immunodeficiency, either congenital or acquired (e.g. HIV infection)
• Having received live vaccine within the past four weeks (e.g. measles, mumps, rubella); BCG vaccination can be given after this interval.
• Febrile conditions
• Severe skin diseases

Parents may consult any one of the chest clinics for further details.