The phase 4 trial is also referred to as post-marketing surveillance, it is conducted after the drug is already marketed and is available to the general public. The main objective of the phase 4 trial is to check the performance of the drug in real-life scenarios, to study the long-term risks and benefits of using the drug, and to discover any rare side effects. As of April 25, 2021 there are 4 vaccines in this phase.
Non-Replicating Viral Vector
Replicating Viral Vector