What is a BCG vaccine?
1. BCG vaccine is a live bacterial vaccine given for protection against tuberculosis, mainly severe forms of childhood tuberculosis.

When is BCG given?
BCG is given anytime from birth to 15 days of life along with the zero dose of oral polio vaccine. It is to be given to all children as part of EPI schedule as recommended by Govt. of India.

How is BCG vaccine given?
BCG vaccine is given over the left arm. A wheal or swelling of 6 mm is raised above the surface. No spirit or antiseptic should be applied over the site before injection. Good bath with soap and water is enough to clean the local injection site. At the most one can use normal saline to clean the area.

What if BCG is not given at birth?
BCG should be given as early as possible in life, before child comes in contact with tuberculosis. It can be given up to 5 years of age. If it is given beyond 6 months it is preferable to do a prior Mantoux test to see if the patient is already sensitized to tuberculosis. If patient is already sensitized as shown by positive MT, BCG is not necessary.

When is a booster dose of BCG vaccine given?
Neither Govt. of India nor Indian Academy of Pediatrics recommends a booster dose of BCG in India. Some countries like in Gulf recommend one or more booster doses.

What is the efficacy of BCG vaccine?
In a country like India where tuberculosis is endemic, children catch the germs early in life & develop primary TB. In children younger than 3-5 years of age, this can spread & lead to severe & serious forms of childhood tuberculosis. BCG being live vaccine itself induces a benign primary infection, which leads to some immunity. Such a child when comes in contact with a patient with tuberculosis can still catch the wild germ and develop primary TB, but the spread will be mostly prevented by previous BCG immunity. Hence such children will not develop serious forms of childhood tuberculosis. Such children when they grow as adults can catch tuberculosis again & develop adult form of tuberculosis which is a different type of tuberculosis altogether. Thus BCG does not prevent adult type of tuberculosis.