Singh, J.A.Kochhar, S.Wolff, J.Atuire, C.Bhan, A.Emanuel, E.Faden, R.Ghimire, P.Greco, D.Ho, C.Moon, S.Shamsi-Gooshki, E.Touré, A.Thomé, B.Smith, M.J.Upshur, R.E.G.2022-04-272022-04-272022https://doi.org/10.1016/j.vaccine.2022.02.038http://ugspace.ug.edu.gh/handle/123456789/37958Research ArticleWhile the degree of COVID-19 vaccine accessibility and uptake varies at both national and global levels, increasing vaccination coverage raises questions regarding the standard of prevention that ought to apply to different settings where COVID-19 vaccine trials are hosted. A WHO Expert Group has developed guidance on the ethical implications of conducting placebo-controlled trials in the context of expanding global COVID-19 vaccine coverage. The guidance also considers alternative trial designs to placebo controlled trials in the context of prototype vaccines, modified vaccines, and next generation vaccinesenPlacebo-controlled trialsStandard of careStandard of preventionTrial designsResearch ethicsArticle