Question

BCG vaccination (Bacillus Calmette-Guerin) gives immunity from

• A. Polio
• B. Cholera
• C. Smallpox
• D. Tuberculosis

Hint:

Recall which bacterium BCG is made from and which disease that bacterium's close relative causes.

Answer 1

The Correct Option is D

Step 1: Understanding the Question.
The question asks which disease the BCG vaccine protects a person against.

Step 2: Key Concept.
BCG stands for Bacillus Calmette-Guerin. It is made from a weakened, live strain of Mycobacterium bovis, a bacterium closely related to Mycobacterium tuberculosis, the germ that causes tuberculosis. In India, BCG is given as a single dose soon after birth under the national immunisation schedule.

Step 3: Detailed Explanation.
Polio is caused by the poliovirus and is prevented using the oral polio vaccine or the injectable polio vaccine, not BCG.
Cholera is a bacterial disease of the gut caused by Vibrio cholerae, and a separate oral cholera vaccine is used for it. BCG plays no part in cholera protection.
Smallpox was caused by the variola virus and was wiped out worldwide using the vaccinia virus vaccine, work that traces back to Edward Jenner. This vaccine has nothing to do with BCG.
Tuberculosis is the disease BCG actually protects against. The weakened bacteria in the vaccine train the immune system to recognise Mycobacterium quickly, so if the person meets the real tuberculosis bacterium later, the body can respond faster and the risk of severe childhood forms such as TB meningitis goes down.

Step 4: Final Answer.
BCG vaccination gives immunity from tuberculosis.