Tuberculosis Elimination Strategy

BCG vaccine: 100 years and counting

Note4Students

From UPSC perspective, the following things are important :

Prelims level : BCG, TB and other respiratory diseases

Mains level : Not Much

The first use of BCG (Bacillus Calmette-Guerin), the vaccine against tuberculosis (TB) in humans have been completed for 100 years.

What is TB?

  • TB is a very ancient disease and has been documented to have existed in Egypt as early as 3000 BC.
  • It is caused by a bacterium called Mycobacterium tuberculosis, belonging to the Mycobacteriaceae family consisting of about 200 members.
  • Some of these cause diseases like TB and leprosy in humans and others infect a wide range of animals. Mycobacteria are also widely dispersed in the environment.
  • In humans, TB most commonly affects the lungs (pulmonary TB), but it can also affect other organs (extra-pulmonary TB).

Yet not eliminated

  • Other historically dreaded diseases like smallpox, leprosy, plague, and cholera have been either eradicated or controlled to a large extent due to advances in science and technology.
  • However, TB continues to be a major public health problem in the world.
  • According to the WHO’s Global TB Report, 10 million people developed TB in 2019 with 1.4 million deaths. India accounts for 27% of these cases.

BCG Vaccine for TB

  • BCG was developed by two Frenchmen, Albert Calmette and Camille Guerin, by modifying a strain of Mycobacterium Bovis (that causes TB in cattle) till it lost its capacity to cause disease while retaining its property to stimulate the immune system.
  • It was first used in humans in 1921.
  • Currently, BCG is the only licensed vaccine available for the prevention of TB.
  • It is the world’s most widely used vaccine with about 120 million doses every year and has an excellent safety record.

BCG in India

  • In India, BCG was first introduced on a limited scale in 1948 and became a part of the National TB Control Programme in 1962.
  • India is committed to eliminating TB as a public health problem by 2025.

Effectiveness of BCG

  • One intriguing fact about BCG is that it works well in some geographic locations and not so well in others.
  • Generally, the farther a country is from the equator, the higher is the efficacy.
  • In children, BCG provides strong protection against severe forms of TB.
  • This protective effect appears to wane with age and is far more variable in adolescents and adults, ranging from 0–80%.
  • In addition to its primary use as a vaccine against TB, BCG also protects against respiratory and bacterial infections of newborns and other mycobacterial diseases like leprosy and Buruli’s ulcer.
  • It is also used as an immunotherapy agent in cancer of the urinary bladder and malignant melanoma.

Try answering this PYQ:

What is the importance of using pneumococcal conjugate vaccines in India? (CSP 2020)

  1. These vaccines are effective against pneumonia as well as meningitis and sepsis.
  2. Dependence on antibiotics that are not effective against drug-resistant bacteria can be reduced.
  3. These vaccines have no side effects and cause no allergic reactions

Select the correct answer using the given code below:

(a) 1 only

(b) 1 and 2 only

(c) 3 only

(d) 1, 2 and 3

 

Post your answers here.
2
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tandonnikita27@gmail.com
tandonnikita27@gmail.com
11 months ago
Post your answers here." Read more »

a

Aishwary Thakur
Aishwary Thakur
11 months ago
Post your answers here." Read more »

b