Sources of pertussis infection in young infants: A review of key evidence informing targeting of the cocoon strategy

► Literature review and pooled data analysis on infant pertussis infection sources. ► Parents were an important source of pertussis infection in very young infants. ► Grandparents were seldom implicated in infant pertussis infection. ► Siblings play a role as pertussis a source, but data is heterogeneous. ► Parents should be the focus of post-partum pertussis immunisation.