Moderna’s Covid-19 vaccine gets FDA O.K. for storage changes, extra dose per vial April 2, 2021 Auto Bot BioPharma, biopharma nl, Cambridge, FDA, Massachusetts, Moderna, Pharma, Vaccines 0 The FDA increased the maximum number of doses permitted for each vial of Moderna’s Covid-19 vaccine, a change intended to make more doses available. The regulator also authorized storage changes for the vaccines at vaccination sites.