CD4 and respiratory syncytial virus bronchiolitis: Although it is known that infants with severe RSV bronchiolitis have increased risks of recurrent wheezing and asthma in later life, previous literature on roles of innate and adaptive cytokines in the pathogenesis of subsequent wheeze following acute severe RSV bronchiolitis have been limited.9 In our study, we have demonstrated impaired TNF‐α production from in vitro CD3/CD28‐activated CD4+ T cells and CD3/CD46‐activated CD4+ T cells during acute illness in children who developed recurrent wheezing following severe RSV bronchiolitis.