Caserta MT, Yang H, Bandyopadhyay S, et al. - Using parent-reported symptoms, researchers created a valid research tool to measure infant respiratory illness severity. In a prospective study of term and preterm infants in the Prematurity, Respiratory Outcomes, Immune System and Microbiome study, nose and throat swabs were obtained monthly for 1 year and during respiratory illnesses for 2 years. Using Taqman Array Cards, viral pathogens were identified. Parents used the Childhood Origins of Asthma (COAST) scorecard to record symptoms during respiratory illnesses. In addition, a data-driven method was utilized to compute symptom weights and derive a new score, the Infant Research Respiratory Infection Severity Score (IRRISS). According to findings, both the COAST score and IRRISS were linked to respiratory syncytial virus infection and hospitalization. Human rhinovirus infection and gestational age were inversely linked to both scoring systems. The authors validated the COAST score using parent-reported symptoms as a measure of the severity of respiratory disease in infants. In addition to the COAST score, the new IRRISS score was performed.