The Covid-19 vaccine is developed in the following manner1:
|Phases of vaccine development or trial||Purpose|
|Pre-clinical phase||In this stage, the vaccine is developed in the laboratory.|
|Phase 1 Clinical trial (8-10 participants)||Phase 1 is essential for testing the safety of the vaccine.|
|Phase 2 Clinical trial (50-100 participants)||Phase 2 is essential for testing vaccine immunogenicity i.e. production of antibodies against viruses.|
|Phase 3 Clinical trial (30,000-50,000 participants)||Phase 3 is essential for testing actual protection offered by the vaccine, i.e, based on a larger survey group.|
Once the vaccine clears phase 3 of the trial, it is eligible to get licensed and becomes available to the public on the basis of government guidelines.0
- COVID-19 Vaccines Operational Guidelines, Ministry of Health and Family Welfare, accessed at https://main.mohfw.gov.in/newshighlights-31 (Page 18).