Overview
- National surveillance for the first 22 weeks of 2026 shows more than 38,000 bronchiolitis cases in Argentina and 563 hospitalizations attributed to respiratory syncytial virus (RSV).
- RSV is the main cause of bronchiolitis and pneumonia in infants under one year, responsible for roughly 60–80% of seasonal bronchiolitis cases and most pediatric respiratory hospitalizations.
- Argentina added maternal RSV vaccination to the national calendar in 2024 and included the long‑acting monoclonal antibody nirsevimab for defined high‑risk infants in 2026, but current eligibility excludes many otherwise healthy, full‑term babies.
- The province of Córdoba has bought about 10,000 doses of nirsevimab to extend protection to infants born from January 1, 2026 who lack maternal immunity, a move that broadens coverage beyond national criteria.
- Clinicians warn that about 80% of severe RSV cases occur in previously healthy, full‑term infants, that seasonal peaks have become less predictable, and that infections can cause longer‑term respiratory problems and added strain on health services.