B.C.G Vaccine is a bovine strain of

Question

Question

This question was previously asked in

RRB Pharmacist Exam Paper 2019

Answer 1

Correct Answer: Mycobacterium tuberculosis

Introduction:

The BCG (Bacillus Calmette-Guérin) vaccine is a vaccine primarily used against tuberculosis (TB). The vaccine contains a live, attenuated strain derived from Mycobacterium bovis, which is closely related to Mycobacterium tuberculosis.

Key Points Related to BCG Vaccine:

Strain: The BCG vaccine is derived from a strain of Mycobacterium bovis, which is a bovine (cattle) pathogen. Over time, this strain was attenuated (weakened) so that it could be used safely in humans to confer immunity against TB.
Development: The vaccine was developed by French scientists Albert Calmette and Camille Guérin in 1921. The name "BCG" stands for Bacillus Calmette-Guérin.
Use: The BCG vaccine is mainly used in countries where TB is common. It is especially effective in preventing severe forms of TB in children, such as TB meningitis and miliary TB.
Mechanism: Upon administration, the vaccine stimulates the immune system to mount a defense against Mycobacterium tuberculosis, the bacterium that causes TB, thereby providing immunity or reduced severity if exposed to the disease.

Explanation of Other Options:

Salmonella typhi

Rationale: Salmonella typhi is the bacterium responsible for typhoid fever. Vaccines for typhoid fever include polysaccharide vaccines and live attenuated Ty21a, but the BCG vaccine is not related to Salmonella typhi.

Hepatitis virus

Rationale: The hepatitis viruses (such as hepatitis A, B, and C) cause liver infections. There are specific vaccines for hepatitis A and B, but the BCG vaccine is not effective against any hepatitis viruses.

Parainfluenza virus

Rationale: Parainfluenza viruses cause respiratory illnesses, particularly in children. The BCG vaccine is not related to these viruses, as it is specific for tuberculosis caused by bacterial infections, not viral ones.

Additional Information:

Tuberculosis: TB is caused by Mycobacterium tuberculosis. It primarily affects the lungs but can also affect other parts of the body. TB is a significant health issue in many parts of the world, especially where the BCG vaccine is widely used.
Global Use: The World Health Organization (WHO) recommends the BCG vaccine for newborns in countries with high TB incidence to provide early protection.
Efficacy: The efficacy of the BCG vaccine varies geographically, and it provides the most protection against severe forms of TB in children.
Safety: The BCG vaccine is generally safe, but it can cause minor side effects like swelling at the injection site. Severe side effects are rare.

Conclusion:

The BCG vaccine is a bovine strain of Mycobacterium tuberculosis, specifically derived from Mycobacterium bovis. It is used to provide immunity against tuberculosis, particularly in countries with a high prevalence of the disease.