In Reply.—That breast-feeding provides protection against GI infections is unquestioned. Indeed, we observed an increased frequency of GI illnesses among formula-fed infants when compared to matched breast-fed infants
(P<.03).1 However, under the circumstances of our study, we found no suggestion that breast-feeding protects against respiratory tract infections. While the study by Pullan et al2 suggests that the severity of RSV infection may be less in breast-fed infants, it does not take into account the total population of either breast-fed or bottle-fed infants with RSV infection. Thus, it is not possible from the base of hospitalized children to draw the conclusion that breast-feeding protects against severe disease due to RSV. Although we cannot entirely exclude a difference in respiratory illness severity from our data, it is noteworthy that the only lower respiratory illness occurred in a breast-fed infant.