Bacillus Calmette–Guerin (BCG) vaccine is a vaccine primarily used against tuberculosis (TB). In countries where tuberculosis or leprosy is common, one dose is recommended in healthy babies as close to the time of birth as possible.

BCG Vaccine and its Protection against Tuberculosis

The BCG (Bacillus Calmette-Guérin) vaccine is primarily given to infants to protect them against tuberculosis (TB) caused by the bacterium Mycobacterium tuberculosis. Let's understand why the correct answer is option 'B' in detail:

What is Tuberculosis?
Tuberculosis is an infectious disease caused by the bacterium Mycobacterium tuberculosis. It primarily affects the lungs but can also affect other parts of the body, such as the spine, kidneys, and brain. TB spreads through the air when an infected individual coughs, sneezes, or talks, releasing tiny droplets containing the bacteria.

How does the BCG Vaccine Work?
The BCG vaccine is prepared from an attenuated (weakened) strain of the bacteria Mycobacterium bovis, which is closely related to Mycobacterium tuberculosis. When the BCG vaccine is administered, it stimulates the immune system to produce a protective response against TB.

Effectiveness of the BCG Vaccine
The BCG vaccine is highly effective in protecting against severe forms of TB in children, such as TB meningitis and miliary TB. It provides variable protection against pulmonary TB (the most common form of TB) in different populations.

It is important to note that the BCG vaccine does not provide complete protection against TB. However, even if a vaccinated individual develops TB, the disease is usually less severe compared to those who have not received the vaccine.

Why is the BCG Vaccine Given to Infants?
The BCG vaccine is typically given to infants because they are at a higher risk of developing severe forms of TB. Infants have immature immune systems, making them more susceptible to TB infection. By administering the BCG vaccine during infancy, the immune system can develop immunity against TB before potential exposure to the bacteria.

Other Vaccines for Different Diseases
Although the BCG vaccine provides protection against TB, it does not protect against other diseases like chickenpox or polio. Different vaccines are available for these diseases, such as the varicella vaccine for chickenpox and the polio vaccine for polio.

Therefore, the correct answer is option 'B' - BCG vaccine protects infants from tuberculosis bacteria. It is crucial to follow the recommended vaccination schedule to ensure infants receive protection against various infectious diseases.

Tuberculosis is correct answer