RSV: the virus that overwhelms infants

By Ana Espino | Published on March 3rd, 2026 | 3 min read


Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infection in infants and young children worldwide. Nearly all children are infected before the age of two, but clinical severity varies widely depending on age, immune status, and comorbidities. In infants under six months, RSV is the leading cause of hospitalization for bronchiolitis.  

Globally, RSV causes millions of respiratory infection episodes each year, with several million hospitalizations and a non-negligible mortality burden, especially in low-resource countries. In high-income countries, its impact mainly manifests as seasonal surges that overwhelm pediatric emergency departments and intensive care units.