
Phase III Vaccine Trials
A successful phase II subject can move on to phase III as long as they didn’t have complications. This phase also has new people because scientists want to test thousands of people; in fact, it’s usually over 10,000 people. They often also look out of their local area and ask in various states or cities. Like the other phases, some subjects are tested with the placebo while other people receive the vaccine. But, there is usually another group that will receive a different vaccine, meaning for another disease that’s already tested thoroughly.
The goal of phase III is to focus on safety and rare side effects. Scientists might notice rare side effects in phase II, but it’ll become more apparent in this phase. The reason why this happens is some side effects occur in 1 of every 10,000 people, so the rare effects don’t usually show until this phase.