BCG Vaccine

(Tuberculosis Vaccine; Bacillus Calmette-Guerin Vaccine)

What Is Tuberculosis?

Tuberculosis, or TB, is an infection from bacteria. It usually affects the lungs. TB can also infect other areas of the body such as the kidneys, spine, or brain.

TB spreads when an infected person coughs or sneezes.

TB is no longer the leading cause of death in the US. However, TB is still a major problem in Africa and other parts of the world. People with HIV also have a higher risk of getting TB.

Symptoms depend on where the bacteria are in the body. In the lungs, TB symptoms may be:

  • A cough that lasts 3 weeks or longer
  • Chest pain
  • Coughing up blood or phlegm
  • Weakness or tiredness
  • Loss of hunger
  • Fever and chills
  • Night sweats

TB can usually be treated with antibiotics. Without treatment, it can be fatal.

What Is the BCG vaccine?

The Bacillus Calmette-Guerin vaccine, or BCG, can help prevent TB. However, this vaccine does not always protect people from getting TB.

The vaccine contains live, weakened bacteria. It is given as shot in the arm.

Who Should Get Vaccinated and When?

The BCG vaccine is advised for:

  • Children who have a negative tuberculin skin test but:
    • Have ongoing exposure to a person who has untreated or drug resistant tuberculosis, and
    • The child cannot be separated from this person
  • Healthcare and lab workers who work where drug-resistant TB is passed

The vaccine is usually given one time. It may be given twice in some cases.

What Are the Risks Associated With BCG Vaccine?

The vaccine may cause some to test positive for TB even though they do not have it. Blood tests can check for TB in those not affected by a prior BCG vaccine.

Common side effects of the vaccine include:

  • Redness at the injection site
  • Fever
  • Muscle aches

Serious side effects are rare. They include serious illness or death.

Symptoms of an allergic reaction require medical care right away.

Who Should Not Get Vaccinated?

The vaccine is not advised for those who:

  • Have a weakened immune system
  • Are undergoing an organ transplant
  • Are pregnant

What Happens in the Event of an Outbreak?

In a TB outbreak, infected people would be given antibiotics and isolated.

Centers for Disease Control and Prevention
The BCG World Atlas on BCG Policies


Basic TB facts. Centers for Disease Control and Prevention website. Available at: Accessed August 24, 2021.
BCG vaccine. DailyMed website. Available at: Accessed August 24, 2021.
Divangahi M, Behr MA. Cracking the vaccine code in tuberculosis. Am J Respir Crit Care Med. 2018;197(4):427-432.
Pulmonary tuberculosis. EBSCO DynaMed website. Available at: Accessed August 24, 2021.
Tuberculosis (TB). American Lung Association website. Available at: . Accessed August 24, 2021.
Tuberculosis (TB) vaccine. Centers for Disease Control and Prevention website. Available at: Accessed August 24, 2021.
Last reviewed July 2021 by EBSCO Medical Review Board David L. Horn, MD, FACP
Last Updated: 8/24/2021

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