BCG vaccine prevents severe tuberculosis illness. Prevalence of tuberculosis/TB varies widely across countries. Hence, criteria for whom and when to give BCG also differs in developing versus developed nations. In this article we will write about, who should get BCG tb vaccine. Also we will simplify tuberculosis vaccine schedule for all. 

Many a times parents are doubtful about BCG vaccination especially when they have a different country of origin but then they migrate. Now baby is born in some other country. What to do in such special circumstances? This blog will give a clear idea on that.

Brief introduction of BCG vaccine

BCG stands for Bacillus Calmette Guérin. Chief component of vaccine is a weak form of TB bacteria, which can generate immunity when it enters human body. But it can not cause tuberculosis the disease. 

BCG tb vaccine is launched after years and years of research. It is in use for more than a hundred years. This vaccine has been successfully preventing death ( mortality) and suffering ( morbidity ) associated with serious tuberculosis. 


Important note

Tuberculosis is caused by mycobacteria. These are known as TB bacteria by common man. It infects human body and gives rise to tuberculosis disease. 

To understand more about tuberculosis, read below article. 

WHAT IS TUBERCULOSIS DISEASE; Symptoms of tuberculosis 

Who should get BCG vaccine in developing versus in developed countries.


BCG candidates in Developing countries

Developing countries are highly endemic to TB. Here case load of tuberculosis disease is maximum. Thus chances are whacking great, that a person will come in contact with tuberculosis infection. 

This interaction with TB bacteria begins during infancy and early childhood. Wherefore in developing countries all infants and young children should be updated with BCG tb vaccine.

BCG candidates in Developed countries

Scenario in developed countries is not the same. Here tuberculosis vaccine is no longer compulsory for all. If a person meets specific criteria as mentioned below then only he/she should follow tuberculosis vaccine schedule. 


Candidates who should get BCG TB vaccine in developed nations are listed below. 


  • If a child belongs to an area having high risk of TB transmission 
  • When parents or grand parents come from a country that is endemic to TB
  • Suppose child contacts with an open tuberculosis case


Additional criteria to give tuberculosis vaccine schedule-


  • If someone has arrived from endemic countries and not yet vaccinated 
  • Supposing a person is going to developing country and planning to stay there for more than 3 months
  • Healthcare workers, including doctors, nurses, lab technicians, hospital management staffs, hospital waste collectors. It even takes into account veterinary staffs.


How many doses of BCG should someone receive?

As stated previously BCG is a live vaccine. Hence only one dose is enough for lifetime. No more second dose or booster dose is indicated. 

TUBERCULOSIS VACCINE SCHEDULE; What is the ideal age to get BCG vaccination ?

The preferred age to begin tuberculosis vaccine schedule is at birth. If missed, then it can be given within 2 weeks of life. If still not given, then consult your paediatrician. S/he will guide you on how to incorporate this vaccine in immunisation schedule of your child. 

CATCH UP AGE FOR BCG ; Up to what maximum age BCG can be given ?

Catch up age for any vaccine is the upper limit of age, upto which a vaccine can be given, if child has bypassed routine schedule. This age varies from country to country. 

1.Developing countries

For developing countries, catch up age for BCG vaccination is up to 1 year. However national schedules of some developing countries recommend that BCG can be given up until 5 years of age. 


2.Developed countries

Also in developed nation, largely BCG is given within 1 year of age. Furthermore, under special circumstances it can be given till 16 years of age. 

Is there any need to give BCG vaccine to more than 16 years old ?

BCG provides insufficient protection against TB lungs in adults. Hence there is no much benefit of giving tuberculosis vaccine schedule after 16 years of age. 

An exemption is “Healthcare workers in developed countries”. In developing part of world by the time a person is 16 years old, s/he is vaccinated or if not, then s/he is already exposed to TB infection. 

But in developed nations usually a >16 years old is still unvaccinated and still vulnerable to tuberculosis infection. In such scenario entering into healthcare profession means high risk of getting in contact with TB bacteria. 

Hence healthcare workers from developed countries, who are between 16 years to 35 years of age and previously not vaccinated, need to receive BCG vaccine.

What is the dose, site and route of BCG TB vaccine?


0.1 ml


Left upper arm


Into layers of skin ( intra-dermal )


Some suggest to give 0.05 ml in <1 year kid and 0.1 ml to more than 1 year kid. But studies say that 0.1 ml dose is warranted for all age groups, even for newborns. 

How long does immunity last following BCG vaccination?

Following BCG vaccination, it takes approximately 6-8 weeks ( i.e. 1-2 months ) to generate immunity against tuberculosis. This immunity lasts roughly 10 years. Afterwards it wanes over time. 

However repeat vaccination has no added benefit, hence not advisable.

To know further in detail about BCG, including what side effects it can produce and which are the individuals where this vaccine should be avoided altogether, read our article 


Efficacy of BCG vaccine for tuberculosis prevention

BCG vaccine’s efficacy is somewhere between 50-80% for serious TB diseases like TB meningitis and Miliary TB. It is most effective for kids under 6 year of age.

When it comes to preventing lung TB in adults, BCG tb vaccine is not reliable. It neither halts tuberculosis infection nor it checks spread of tuberculosis bacteria from a person to another person. 

As discussed earlier, the primary goal of BCG vaccination is to reduce death and suffering related to severe form of TB in children. 

Is a child completely safe after taking BCG tb vaccine?


No. Efficiency of BCG is not 100% and not even close to that value. Thus a vaccinated child may still catch tuberculosis. However severity of illness will not be as much. 

What to do when a previously vaccinated kid comes in contact with an open TB case ?

If a formerly vaccinated kid comes in contact with a person having infectious tuberculosis then what to do ? If the kid shows symptoms of TB then evaluate with x ray, sputum test etc. 

On the other hand if kid is asymptomatic, then give chemoprophylaxis ( prescription medication to prevent tuberculosis ).


Share this piece of knowledge to maximum and help all parents out there to understand tuberculosis vaccine schedule in a simple way. If you have any other query related to BCGtb vaccine then comment below. 


All the informations provided here are for educational and awareness purpose only. Kindly do not use these as alternative to medical consultation.

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