Horizontal transmission of a human rotavirus vaccine strain-A randomized, placebo-controlled study in twins

► Transmission of excreted vaccine-derived infectious virus from vaccinated to unvaccinated individuals was assessed. ► Presence of vaccine strain in the stool samples of placebo recipients was an indicator of transmission. ► Immunogenicity and safety of HRV vaccine in transmission cases was assessed. ► Transmission rate was 18.8%; however, they were not associated with increased risk of gastroenteritis.