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)
- These vaccines are effective against pneumonia as well as meningitis and sepsis.
- Dependence on antibiotics that are not effective against drug-resistant bacteria can be reduced.
- 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.