The Respiratory Syncytial Virus (RSV) has become the primary viral agent detected among patients hospitalized for severe respiratory infections in Argentina, according to the latest National Epidemiological Bulletin (BEN). The disease, which causes bronchiolitis and is the leading cause of infant hospitalization, continues to place sustained pressure on the pediatric healthcare system.
Alarming Data on Respiratory Infections
According to the BEN No. 819, over 65,000 cases of bronchiolitis were recorded nationwide up to epidemiological week 28 of 2026. So far this year, 2,267 hospitalizations with RSV detection have been reported, a figure that significantly exceeds flu hospitalizations in the same age group.
Virus circulation has been steadily rising since week 13, and from week 23 onwards, it has surpassed 100 weekly cases. Between weeks 28 and 29 alone, 563 detections were registered, while influenza has already begun to decline after its peak.
What is RSV? It is a highly contagious respiratory virus that primarily affects children under 2 years old. It can cause bronchiolitis (inflammation of the small airways) and pneumonia. It is transmitted through saliva droplets and contact with contaminated surfaces.
The Most Affected: Infants Under 1 Year Old
Surveillance data confirms that infants under one year of age concentrate the highest number of positive cases, both in outpatient consultations and hospitalizations. Children under 5 are the most vulnerable group, and within this group, infants are at the highest risk of developing severe forms of the disease.
Dr. Néstor Vain, Head of Neonatology and Pediatrics at Sanatorios de la Trinidad Palermo and Ramos Mejía, warned: “The majority of children who develop severe illness were born healthy and full-term, with no known risk factors. All babies are at risk of getting sick.”
Key Figures
- 🔴 65,000+ bronchiolitis cases
- 🏥 2,267 RSV hospitalizations
- 📈 563 detections in weeks 28-29
- 👶 10,000 doses of nirsevimab in Córdoba
Why It Matters
Historically, RSV is the leading cause of death in babies after the first month of life up to their first birthday, according to pediatric records.
The Prevention Gap
Argentina incorporated maternal vaccination against RSV into the National Calendar in 2024, a significant advancement. However, specialists point out that not all babies arrive protected for their first viral circulation season.
- Births outside the vaccination period: babies born between October and December do not receive enough maternal antibodies for the May-June peak.
- Incomplete coverage: vaccination adherence among pregnant women is around 65-70%, well below other immunization schedules.
- Waning protection: transferred antibodies last between 5 and 6 months, leaving babies unprotected during the remainder of their first year.
Dr. Analía De Cristófano, Head of Pediatric Infectious Diseases at the Hospital Italiano, explained that the maternal vaccine reduced severe cases but not overall hospitalizations as much. “Children born towards the end of the year arrive without antibodies at the contagion peak,” she noted.
The Solution Already Applied in Córdoba
Faced with this situation, the province of Córdoba became the first in the country to implement a combined strategy: it incorporated nearly 10,000 doses of nirsevimab, a long-acting monoclonal antibody that protects babies during their first season of viral circulation.
The Cordobese strategy includes:
- Administration to newborns before discharge in maternity wards and authorized vaccination centers.
- Children born since January 1, 2026 who meet eligibility criteria.
- Babies with risk conditions born since September 1, 2025.
Dr. María Soledad Álvarez, from the Hospital Infantil Municipal de Córdoba, stated that “health teams are beginning to observe signals that could be consistent with a favorable impact from this integrated strategy.”
What Do Scientific Societies Recommend?
The Argentine Society of Pediatrics (SAP), the Argentine Society of Vaccinology and Epidemiology (SAVE), the Argentine Society of Pediatric Infectology (SADIP), and the Latin American Society of Pediatric Infectology (SLIPE) recommend advancing towards a strategy that combines maternal vaccination with monoclonal antibodies for uncovered babies.
The Real Impact: according to Dr. Vain, the maternal vaccine reduces total bronchiolitis by 25-30%, while combined strategies decrease it between 80% and 90%. In Chile, which administers nirsevimab to 100% of babies born between April and October, they achieved a 93% reduction and zero deaths from this cause.
Other provinces like Santa Fe and San Juan are also advancing in the incorporation of nirsevimab according to their health strategies. Dr. Vain concluded with a call for equity: “It is unfair that healthy children are going to catch a preventable disease. Our hope is that the strategy adopted by Córdoba soon becomes a national strategy.”
Sources: El Destape | Infobae | La Nueva | LU17 | La Arena