Bronchiolitis: Beyfortus helped avoid thousands of hospitalizations in France, according to a study

Beyfortus, a treatment intended to limit the risks of bronchiolitis in babies, made it possible to avoid thousands of hospitalizations this winter in France, concludes a study published Friday by the health authorities. According to this work, carried out by the Pasteur Institute and the French Public Health agency, Beyfortus, which served as the basis for a vast vaccination campaign in recent months, was able to avoid hospitalizing between 3,700 and 7,800 babies.

Developed by the pharmaceutical giant Sanofi from the molecule nirsévimab, Beyfortus is a treatment which aims to limit infections by the respiratory syncytial virus (RSV), the main cause of bronchiolitis. This mainly affects infants in whom it causes respiratory problems. It is generally not serious, but can sometimes require hospitalization. Until recently, there was no preventative treatment for RSV. The situation changed last year with the arrival of Pfizer’s Abrysvo vaccine and Beyfortus, which does not work according to the principle of vaccination but has the same immunization objective.

A significant number of babies hospitalized

This bronchiolitis season is therefore the first which makes it possible to evaluate the effectiveness of these treatments in real life, more than 200,000 doses of Beyfortus having been distributed in France. In the country, the bronchiolitis epidemic was less this year than the particularly violent one of 2022-2023, but a significant number of babies were nevertheless hospitalized. Initial observations would show a lower frequency of hospitalizations among newborns, to whom Beyfortus was ultimately directed as a priority. The study by Public Health France and Pasteur went into much more detail than these observations, taking into account factors such as the conditions of administration of Beyfortus as well as the profile of epidemics in different years.

It therefore concludes that the treatment is effective against hospitalizations, which is in line with studies carried out in other countries such as Spain where the treatment has also been deployed en masse. Another work, published simultaneously by Public Health France and the Pasteur Institute, goes in the same direction, but with another methodology: the researchers studied a group of infants hospitalized in intensive care for bronchiolitis, and looked at whether they had received Beyfortus or not. They estimate that the treatment is 75% effective against the need for intensive care, a figure which must however be put into perspective by the relatively small size of the sample of around 300 babies.