Next steps for efficacy evaluation in clinical trials of COVID-19 vaccines

Jiang, Hu-Dachuan; Zhang, Li; Li, Jing-Xin; Zhu, Feng-Cai

There are currently ten COVID-19 vaccines being announced their preliminary efficacies from phase 3 clinical trial, and nine of them have been authorized for emergency use or conditional licensed, which brings some issues to present placebocontrolled efficacy trial of other COVID-19 vaccines. The approval of “first wave” COVID-19 vaccines raises concerns about the administration of a placebo in ongoing and future phase 3 trials of COVID-19 vaccine candidates. Comprehensive efficacy assessment strategy for the next steps is now required. This perspective covers challenges for ongoing COVID-19 vaccine clinical studies and alternative clinical study designs in the future, under the placebo use being acceptable or unacceptable circumstances, respectively, in order to ensure the safety, efficacy and effectiveness evaluation of COVID-19 candidate vaccines pre- and post-licensure.