In enteric viral infections, such as those with rotavirus and norovirus, individual viral particles shed in stool are considered the optimal units of fecal-oral transmission. We reveal that rotaviruses and noroviruses are also shed in stool as viral clusters enclosed within vesicles that deliver a high inoculum to the receiving host. Cultured cells non-lytically release rotaviruses and noroviruses inside extracellular vesicles. In addition, stools of infected hosts contain norovirus and rotavirus within vesicles of exosomal or plasma membrane origin. These vesicles remain intact during fecal-oral transmission and thereby transport multiple viral particles collectively to the next host, enhancing both the MOI and disease severity. Vesicle-cloaked viruses are non-negligible populations in stool and have a disproportionately larger contribution to infectivity than free viruses. Our findings indicate that vesicle-cloaked viruses are highly virulent units of fecal-oral transmission and highlight a need for antivirals targeting vesicles and virus clustering. Display omitted •Rotaviruses and noroviruses are shed in stool as viral clusters inside vesicles•Vesicles containing virus clusters remain intact during fecal-oral transmission•Vesicles achieve a high MOI and induce severe disease•Vesicle-cloaked viral clusters are more virulent units than free viral particles Freely disseminating standalone viral particles are considered the optimal agents for spreading infection. Santiana et al. discover that enteric viruses are also shed in feces as viral clusters cloaked in vesicles. These virus-containing vesicles are a more potent infectious form that enhances the MOI and disease severity.