Figure 1

Flow chart of the birth cohort study: demonstrating the number of participants at each age period. 423 infants at the age of 12 months had complete questionnaire results and blood tests (complete blood count), 388 had nasopharyngeal specimen (NP) for bacterial identification, and 286 infants had peripheral blood mononuclear cell (PBMC) available for TLR stimulation. Valid questionnaire information and medical records in regard to infectious diseases were available for 302 children at the age of 24 months and 184 at the age of 36 months.