07-05-2025
Does Nirsevimab Help Prevent Severe RSV Infections?
Among 69 hospitalisations of infants for respiratory syncytial virus (RSV)–related lower respiratory tract infection (LRTI) in a Spanish study, 65.2% occurred despite the administration of nirsevimab. A large proportion of the hospitalised infants had high-risk conditions and needed oxygen support, with no significant differences observed between breakthrough and non-breakthrough cases.
METHODOLOGY:
Researchers conducted NIRSE-GAL, a prospective observational study between 2023 and 2024 across 14 public hospitals in Galicia, Spain.
A total of 69 infants (median age at admission, 2.7 months; 56.5% boys) who received nirsevimab and were hospitalised for RSV-related LRTI were included.
Cases were classified as breakthrough (n = 45) or non-breakthrough (n = 24). Breakthrough cases were defined as those in which nirsevimab was administered at least 7 days before admission with no observation of clinical symptoms compatible with RSV infection within 7 days post-administration and no RSV-positive test result in the 15 days before immunisation.
Sociodemographic, clinical, and hospitalisation-related data were obtained and analysed.
TAKEAWAY:
The median length of hospital stay was 4 days among breakthrough cases.
Among all hospitalised infants, 23.2% had high-risk conditions, 63.8% required oxygen support, 21.7% needed admission to the intensive care unit, and 15.9% received non-invasive mechanical ventilation. No significant differences in terms of these characteristics were found between breakthrough and non-breakthrough cases.
The incidence of cases paralleled the RSV epidemic curve, suggesting that the efficacy of nirsevimab did not wane over time.
IN PRACTICE:
"During the first RSV season after the universal implementation of nirsevimab in Galicia (Spain), a large proportion of hospitalized infants had high-risk conditions, yet disease severity markers (oxygen need, ICU [intensive care unit] admission, NIVM [non-invasive mechanical ventilation]) were comparable between breakthrough and non-breakthrough cases," the authors wrote. "No signal of waning protection over time was observed among breakthrough cases, reinforcing the potential value of early, season-wide immunization," they added.
SOURCE:
This study was led by Angela Manzanares, Hospital Clínico Universitario de Santiago and University of Santiago de Compostela, Santiago de Compostela, Spain. It was published online on May 02 in the European Journal of Pediatrics .
LIMITATIONS:
The study had a small sample size, which may have reduced the statistical power and limited the application of complex analyses. Data were obtained only from public hospitals.
DISCLOSURES:
The NIRSE-GAL study received funding from Sanofi/AstraZeneca (through a research grant to the Healthcare Research Institute of Santiago) and a Framework Partnership Agreement between Consellería de Sanidad de la Xunta de Galicia and GENVIP-IDIS-2021-2024. Additional funding came from ISCIII, GAIN, ACIS, Consorcio Centro de Investigación Biomédica en Red de Enfermedades Respiratorias, the Galician Supercomputing Center, the Spanish Ministry of Science and Innovation, the Galician Government, and the European Regional Development Fund, the European Seventh Framework Programme for Research and Technological Development. Several authors reported acting as investigators in clinical trials for pharmaceutical companies, with honoraria paid to their institutions. Some also disclosed having consulting, advisory, or employment ties and possibly holding shares or stock options with various companies.
