Authors´ conclusions: MMR vaccination was associated with reduced rate of hospital contacts related to laboratory-confirmed RSV infection. Further research on the association between MMR vaccination and other unrelated pathogens are warranted.
Reviewers´ commentary: the results of this study show a non-specific protective effect of the MMR vaccine, with a decrease in the incidence of respiratory syncytal virus (RSV) infection in children, to a greater extent when more time passed from the day of vaccination. Although this is a cohort study, with the risk of bias, it meets the quality criteria required for this type of study. When informing parents about vaccines, we could tell them that the MMR vaccine could decrease the risk of serious RSV infection, an illness with high incidence in early life.