The use of vaccines and immunisation programmes have enabled us to completely eradicate a deadly disease like

Options

A. Polio
B. Tetanus
C. Diphtheria
D. Small pox

Explanation

**Step-by-Step Text Solution:**

1. **Understanding Vaccines and Immunization:**
Vaccines are biological preparations that provide acquired immunity to a particular infectious disease. Immunization programs are organized efforts to vaccinate populations to prevent the spread of diseases.

2. **Identifying the Disease:**
One of the most notable successes of vaccination and immunization programs is the complete eradication of smallpox. Smallpox was a highly contagious and deadly disease caused by the variola virus.

3. **Historical Context:**
The vaccine that led to the eradication of smallpox was discovered by Edward Jenner in 1798. His work laid the foundation for immunology and the use of vaccines to combat infectious diseases.

4. **Mechanism of Action:**
The smallpox vaccine works by introducing a harmless form of the variola virus into the body, prompting the immune system to recognize and fight the virus. This prepares the immune system to respond effectively if exposed to the actual virus in the future.

5. **Outcome of Vaccination:**
Due to widespread vaccination efforts, smallpox was declared eradicated by the World Health Organization (WHO) in 1980. This marked a significant milestone in public health and demonstrated the effectiveness of vaccines.

6. **Conclusion:**
The eradication of smallpox is a prime example of how vaccines and immunization programs can eliminate deadly diseases, showcasing the importance of vaccination in global health.

---