The heads of Pediatrics at Lisbon’s Dona Estefânia and Santa Maria hospitals have reported a significant reduction in pediatric cases of severe respiratory infections as their vaccination campaign draws to an end. Dona Estefânia has seen cases decrease by two-thirds, while Santa Maria noted a drop in intensive care admissions from an average of 40 to just five infants.
The Respiratory Syncytial Virus (RSV) is a prevalent cause of pediatric infections, particularly bronchiolitis, and contributes to annual seasonal epidemics, placing a burden on healthcare services.
Last year, Portugal’s Directorate-General of Health implemented a free immunization program for children born between August 1, 2024, and March 31, 2025, among other specified groups.
Francisco Abecassis, the head of Pediatrics at Hospital Santa Maria, described the effect of this immunization as “dramatic,” noting that critical care cases had “virtually disappeared.” He stated, “In 2022/2023, we had 37 bronchiolitis cases in intensive care. In 2023/2024, there were 30. The average is usually between 30 and 40. This season we had five,” explaining that only three were due to RSV, and these were in older, unvaccinated children.
“This has effectively eliminated the disease in intensive care, thanks to this strategy,” he added.
Abecassis noted that children with bronchiolitis were still admitted to the pediatric pulmonology ward, although those numbers have declined. A study comparing the October to December period over the past four years showed a decrease from 60-100 cases to 48 this year. He highlighted that “the highest difference was the average age of hospitalized children, which was around two and a half months previously, and is now nine months.”
Abecassis is confident that these results stem from the vaccination effort: “Cases of severe bronchiolitis in infants and newborns have nearly vanished. This reflects the success of the immunization strategy since RSV is still present but mostly in older children.”
Similarly, the vaccination had positive outcomes at Hospital Dona Estefânia. While the average number of hospitalizations did not decrease significantly, the head of Pediatrics, Luis Varandas, observed a change in the profile of admitted children.
“In 2023/24, around 70% of RSV hospitalizations occurred in children under six months old, with smaller numbers in older age brackets. Now, about 45% of cases are in infants under six months,” Varandas explained, noting that “65% of these should have been vaccinated but were not.”
Both specialists pointed out issues with the immunization campaign’s start, which was delayed from October 1 to October 15 and varied in rollout speed across different areas.
Regarding emergency visits, there was a “significant decrease,” though this cannot be directly attributed to the immunization as not all children are tested for RSV, only severe cases. Laboratory data for tested children show a reduction of two-thirds.
When asked about extending the immunization age range, Abecassis emphasized the need for a study to evaluate cost-benefit ratios given the high price of the monoclonal antibody. Varandas concurred, advocating for broad-based vaccination while acknowledging cost-effectiveness constraints.
“Focusing on infants over three months might be more cost-effective since we can target more precisely and reduce spending. However, as evidenced, this excludes many from immunization,” noted Varandas, emphasizing the equity issue: “Why should a child born on August 1 be entitled to immunization while another born on July 31 is not?”
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