<prompt> Answer this question truthfullyWhat is the respiratory syncytial virus in humans?  <response>: <reason> Prematurity Bronchopulmonary Dysplasia Congenital Heart Disease Neuromuscular Impairment Immunodeficiency Immunosuppression Down SyndromeAge 6 months at the beginning of the RSV season Multiple birth Male sex Low socio-economic status and parental education Crowded living conditionssiblings Maternal smoking and indoor smoke pollution Malnutritionsmall for gestational age Family history of atopy of asthma Low cord serum antibody titers Living at altitudeBirth before or during RSV season Day care attendanceolder siblings in school or day-care Lack of breastfeeding 