diseases, but lacking biospecimens. Thus, we designed the prospective TCRI to establish a base for the evaluation of both the risks and benefits of documented significant infant viral respiratory infection of varying severity and aetiology and other environmental exposures on childhood atopy outcomes and to establish a biospecimen repository for analyses including biomarker testing and genotyping. The prospective cohort has the longitudinal design properties that may overcome potential limitations intrinsic to retrospective studies, such as our TABS cohort. [1] [2] [3] [4] [5] It is our eventual goal that the findings from these investigations, in conjunction with other investigations that have helped to elucidate genetic and environmental factors associated with asthma development, will help in the identification of primary and secondary prevention strategies for asthma. This report describes the study objectives, design and recruitment results of this study cohort.