CLEAN : Ebola vaccine trials begin in Liberia

The video discusses a study on vaccines, focusing on their effectiveness and safety. It outlines the study's objectives, such as determining the duration of protection against Ebola and the safety of the vaccines. The mechanism of vaccines is explained, highlighting how they expose the immune system to build immunity. The study involves several phases, with a significant number of participants to ensure comprehensive results. The ultimate goal is to ensure that future exposures to the virus result in milder symptoms, reducing the risk of severe outcomes.

What is the significance of the number of participants mentioned in the study?

What factors are considered when studying the safety of the vaccine?