Who is at particular risk from RSV infection?
For most people, RSV infection causes a respiratory illness that is generally mild. For a small number of people who are at risk of more severe respiratory disease, RSV infection might cause pneumonia or even death. RSV is best known for causing bronchiolitis in infants. Bronchiolitis occurs when the tiny airways leading to the lungs, called bronchioles, become inflamed and fill with mucus, making it difficult for a child to breathe. Over 60% of children have been infected by their first birthday, and over 80% by two years of age. The antibodies that develop following early childhood infection do not prevent further RSV infections throughout life. The full extent to which adults are affected by RSV remains unknown.
