BCG VACCINE

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.

Why is BCG not recommended in USA?
In developed countries like USA, very few cases of tuberculosis occur. As BCG does not prevent primary TB or the adult type of tuberculosis no benefit will be derived by routine BCG vaccination in such countries. Hence BCG is not recommended in USA routinely.

What is the normal reaction to BCG vaccine?
Immediately after the BCG vaccine there is a small swelling at the injection site, which persists for 6-8 hours. After that the swelling disappears & the injection site looks normal. After 6-8 weeks a swelling reappears, which looks, like a mosquito bite. It grows in size & forms a nodule, which breaks open & discharges some fluid & forms an ulcer. The ulcer heals by forming a scar. The whole process takes 2-5 weeks. Some times this process of ulceration & healing recurs 2-3 times. Ultimately the typical puckered scar is formed which remains for lifetime.

If ulceration occurs within 7 days of injection, one must report to the doctor, as it may be a sign of tuberculosis in the child.

What local care should we take at injection site?
Injection site should not be pressed or rubbed. It should not be fomented. Nothing needs to be applied locally. Infact, bath with soap and water should suffice even when it has ulcerated.

What if the child develops fever?
BCG does not lead to fever. Hence search for another cause & treat accordingly.

Can BCG be given over thigh from beauty point of view so that scar is hidden?
By convention BCG scars are looked for over the left arm & hence it is easier to recognize for the doctor when parents do not remember whether BCG was given in the past or not. Hence BCG should only be given over left arm & nowhere else.

What if scar is not seen after BCG vaccination?
Formation of scar is neither necessary nor is the only indication of success of BCG vaccine. However it is the only simple & convenient way of determining success of BCG vaccine. It may take 3-6 months for the scar to form. If no scar is visible at all after 6 months one needs to do Mantoux test. If negative, one should give repeat BCG

Can BCG be given with other vaccines?
BCG can be given with other vaccines except Measles and MMR. In fact, BCG is given along with zero dose of OPV & 1st Dose of Hepatitis B vaccine at birth. BCG should not be given along with measles or MMR

What are the complications of BCG?
In 1-2 % of vaccinees, local gland can get swollen. Consult your doctor if it remains the same.

 

Last updated on 02-12-2003