This might give a clue as to where China is at. Apparently there aren't enough cases in mainland for phase 3 trials, so their vaccine is being trailed in Brazil. One article says 900 healthcare workers taking the trial, another says 9000. 9000 is probably more like it for a final stage.
https://medicalxpress.com/news/2020-...s-vaccine.html
https://www.bangkokpost.com/world/19...ests-in-brazil