> Listen on Spotify > Listen on Apple Products > Listen on Amazon Music > Listen on iHeart Last week, the FDA declined to review Moderna’s mRNA-based flu vaccine, with Center for Biologics Evaluation and Research Director Vinay Prasad himself signing the refuse-to-file (RTF) letter. Prasad said Moderna’s comparator group “does not reflect the best-available standard of care,” while Moderna pushed back, saying CBER had previously found a standard-dose flu shot to be an “acceptable” comparator.