Ali Siftain, Mamoona Chaudhry, Taiba Zulfiqar, Syed Ali Kaunain and Muhammad Sher Zaman ABSTRACT Background: Viral infection of the respiratory tract is a common illness syndrome in humans. Human respiratory tract is infected by large number of viruses. Self-constraining infections are caused by most of them e.g. normal chilly and intense bronchitis. Seriousness of illness […]