CLINICAL TRAIL OF VACCINE

 Vaccine improve human and animal health by preventing the spread of infections. When once the vaccine is developed, it undergoes several tests and it may take several months or years.

At first testing of vaccine to ensure safety. It is done on large number of animals, later it undergoes clinical trail. Clinical trail are governed by strict regulation. Clinical trail takes place in 3 phases but sometime four phase may also be necessary.

Phase 0

phase 0 clinical trail is done with very small number of people,usually less than 15. Investigators use very small dosage of medication to make sure it isn't harmful to humans. If the medication cause any harm, the investigators will do some additional preclinical research before deciding to proceed.

Phase 1

In this phase it is medicated to people who have no health issues and spend several month on looking at its effectiveness. About 20 to 80 people undergo clinical trail in this phase. This phase aims to figure out the highest dose that human can take without serious effect. Investigators monitor participants very closely to see how their body react to medication. According to FDA about 70% of medication move to next phase.

Phase 2

This phase includes several hundreds of participants .They usually give the same dose as in previous phase. They're monitored for several months or years to see how effective the medication is or does it cause any side effects. Data collected in this phase helps investigators to come up with methods for conducting next phase. FDA estimates about 33% of medications move to phase 3.

Phase 3

In this phase about 3000 participants are involved and this can last for several years. The main aim of this phase is to evaluate how medication works .In this phase investigators need to demonstrate that medication is safe and effective. Due to larger number of participants and longer duration it may show some side effects. According to FDA 25% to 30% of medication move to phase 4.

Phase 4

Phase 4 involves several thousands of participants and may last for many years. Investigators use this phase to get more information of medication, like its effectiveness and many other benefits. This phase happens only after the approval of FDA.

Clinical trail is very important as it helps to know about the effectiveness of drugs before it is provided for public use. 

-  Drishya D R