Subject: Science & Technology

The development of vaccines stands as one of humanity's greatest scientific achievements in combating infectious diseases. The journey from disease identification to vaccine deployment involves complex scientific principles and rigorous testing protocols.

Basic Principle of Vaccine Development

• The fundamental principle relies on training the immune system to recognize and fight specific pathogens without causing the actual disease.
• Vaccines contain either weakened pathogens, killed pathogens, or parts of pathogens that trigger an immune response.
• The development process involves extensive pre-clinical trials, followed by three phases of human trials to ensure safety and efficacy.

Working Mechanism of Vaccines

• Vaccines stimulate the production of antibodies and memory B-cells that remember how to fight specific pathogens.
• When vaccinated individuals encounter the actual pathogen, their immune system:
  • Quickly recognizes the threat.
  • Mounts a rapid immune response.
  • Prevents or reduces disease severity.

Indian Approaches to COVID-19 Vaccine Development

• Indigenous Development:

  • Bharat Biotech, in collaboration with ICMR-NIV, developed COVAXIN using traditional inactivated whole-virion technology.
  • Phase 3 trials showed 77.8% efficacy against symptomatic COVID-19.

• Technology Transfer:

  • Serum Institute of India manufactured Covishield through technology transfer from AstraZeneca.
  • Achieved a production capacity of 120 million doses monthly by December 2021.

• Distribution Strategy:

  • Initially, government procured 100% of vaccine doses (January-April 2021).
  • Later modified to 75% government procurement with free distribution to states.
  • Successfully exported 162.9 million doses by February 2022.

India's success in developing and manufacturing COVID-19 vaccines demonstrates its emergence as a global pharmaceutical hub and validates its "Make in India" initiative. The country's vaccine development approach combining indigenous research with international collaboration serves as a model for future pandemic preparedness.