>They didn't contract Covid, but we're they exposed to it in a lab environment, or just set off on their way to be evaluated x months later? This is what is re

>They didn't contract Covid, but we're they exposed to it in a lab environment, or just set off on their way to be evaluated x months later? This is what is referred to as a 'challenge trial'[0]. It is something the UK is apparently working on but afaik, neither of the current vaccine candidates have used any form of challenge trial. This is one of the difficulties with vaccine testing...if I were to vaccinate everyone in the world against small pox, how do I prove it's effectiveness? [0] https://www.the-scientist.com/news-opinion/a-challenge-trial-for-covid-19-would-not-be-the-first-of-its-kind-68030 https://www.the-scientist.com/news-opinion/a-challenge-trial... Edit: for some fun, I figured I should link to the 'COVID challenge trial volunteers advocacy organization'. Yes, an advocacy group for people who want to be infected with COVID. https://1daysooner.org/ https://1daysooner.org/