(Paris) The Beyfortus, treatment intended to immunize babies against the main virus that causes bronchiolitis, is very effective in preventing serious infections by the syncytial respiratory virus (VRS) in infants, confirms a large analysis published on Friday.
Posted at 7:44 a.m.
National studies had already concluded that this treatment had limited the hospitalizations of babies, but that revealed in The Lancet Child & Adolescent Health gives the most solid panorama of the state of knowledge.
If it is generally without gravity, bronchiolitis, which causes breathing difficulties, especially for babies during the first six months of their lives, can sometimes lead to emergency and hospital passages.
The Beyfortus is part of a series of innovative treatments which aim to prevent or limit infection by the main virus behind this disease. Nirsevimab, the name of the molecule, is not a vaccine even if it is injectable, but a preventive treatment preventing the virus from infecting the body.
After successful clinical trials, this monoclonal antibody – developed by Sanofi in partnership with the British Astrazeneca – was approved by several regulatory agencies in 2023 and then made available in certain high -income countries.
According to the meta-analysis published on Friday, 27 studies carried out during the 2023-2024 VRS season in five countries (France, Italy, Luxembourg, Spain, United States), the Norsevimab reduces by average the risk of hospitalization due to a infection by the main bronchiolitis virus, 81 % intensive care admission and 75 % Lower respiratory in children 12 months and less.
This immunization seemed more effective to prevent the hospitalization of infants over 3 months (81 %) than those of 3 months or less (76 %), observed its authors.
The efficiency of the Norsevimab on the reduction of hospitalizations linked to bronchiolitis, however, appeared variable depending on the country, higher in the United States (93 %) than in Spain (83 %) and in France (76 %).
Possible explanation, according to the researchers: a higher proportion of high risk infants of serious infection received this treatment in the United States, where this category was a priority during the 2023-2024 bronchiolitis season due to limited supply in beyfortus. It would take further research to verify this hypothesis.
This meta-analysis has limits, recognize its authors. The studies taken into account were observational, which can lead to bias linked to underlying health problems, socio-economic status or regional differences in care access.
