B.C.G. Vaccination (Bacillus Calmette Guerin)
No vaccine has generated more controversy than BCG vaccination. The vaccine is a live attenuated strain of Bovine Mycobacterium tuberculosis. The vaccine was developed by Calmette and Guerin in 1921. The principle is to give controlled infection with
a live attenuated bacillus, which will induce hypersensitivity and immunity. Subsequent exposure to infection will be contained locally without general dissemination. Trials have been done in different parts of the world to assess the efficacy of the
vaccine and protection rate ranges between 0% and 100% BCG has little impact on annual incidence risk of tuberculous infection, but considerable impact on child mortality by preventing dissemination of infection. There is uniform agreement that serious manifestations of tuberculosis like tuberculous meningitis are less common among children who received BCG vaccination. However, a vaccine obtained by Genetic recombinant technique to prevent the infection itself would be ideal.
The present recommendation is to administer BCG at birth, preferably within 4 weeks of life. It is given intradermally, 0.1 ml at the insertion of deltoid muscle on the left side. One expects a local reaction at the site of vaccination over a period of 4 to 8 weeks leaving a puckered scar and also a mild enlargement of anterior axillary lymphnodes on the same side. A positive tuberculin test 6-8 weeks after vaccination signifies a successful vaccination. BCG vaccination can safely be given at any age after a prior negative tuberculin test.
Efficacy variable in different studies
Mortality and serious manifestations are less in children receiving BCG
Administer at birth or at least within 4 weeks of life