Cell study in primates compares Moderna mRNA-1769, MVA and ACAM2000 mpox vaccines

A head-to-head non-human primate study published in Cell compared three mpox vaccine candidates after lethal clade 1 intravenous challenge: MVA and Moderna's lipid nanoparticle mRNA vaccine mRNA-1769 both prevented deaths while all controls died. mRNA-1769, targeting four conserved orthopoxvirus epitopes, produced about 50 to 60 total skin lesions versus about 600 for MVA and about 1600 in controls. The trial was industry-run, and intravenous challenge does not model natural human infection, so independent post-marketing data are needed.