Ahh the Human Respiratory Syncytial Virus - more commonly known as RSV. The last 2 times we' ve met it's been sick infants, ambulance calls, & in 1 case a hospital admit. In the United States, 60% of infants are infected during their first RSV season, and nearly all children will have been infected with the virus by 2–3 years of age. Of those infected with RSV, 2–3% will develop bronchiolitis, necessitating hospitalization. Nasty stuff.
You wanna know why? Listen to this: treating respiratory syncytial virus bronchiolitis "remains a good example of therapeutic nihilism—nothing works except oxygen". Adrenaline, bronchodilators, steroids, and ribavirin confer "no real benefit".