Unblinding
https://www.bmj.com/content/373/bmj.n1244
Pfizer declined to say, but Moderna announced that “as of April 13, all placebo participants have been offered the Moderna covid-19 vaccine and 98% of those have received the vaccine.”2 In other words, the trial is unblinded, and the placebo group no longer exists.
Uridine Residues
https://www.nature.com/articles/s41435-021-00136-6
Noteworthy, the mRNA does not include any uridine residues; however, they are replaced by 1-methyl-3′-pseudouridylyl [3].