mRNA-1345 + mRNA-1365

mRNA-1345 + mRNA-1365 is a combination of two investigational mRNA-based vaccines developed by Moderna for the prevention of respiratory viral infections in pediatric populations. mRNA-1345 encodes a stabilized prefusion F glycoprotein of respiratory syncytial virus (RSV), designed to elicit strong neutralizing and binding antibody responses to RSV-A and RSV-B subtypes. mRNA-1365 encodes viral antigens from both RSV and human metapneumovirus (hMPV), aiming to provide broad protection against both pathogens. Both vaccines use lipid nanoparticle (LNP) formulations to deliver the mRNA payloads. Clinical trials are ongoing primarily in infants and young children; however, dosing in at least one trial has been paused due to safety concerns regarding severe RSV-associated lower respiratory tract illness following vaccination in young infants[1][5][6][7][9][11].