You do know the difference between an emergency use and an actual approved vaccine? Did you know that the "emergency" use is experimental for a reason?
"an experimental drug" synonyms: exploratory · investigational · probing · fact-finding · trial and error · trial · test · pilot · speculative · conjectural · hypothetical · tentative · preliminary · probationary · prototype · under review · under the microscope · on the drawing board · empirical · observational · untested · untried