The figure was eagerly awaited. 5,800 hospitalizations of babies in emergency rooms for bronchiolitis has respiratory syncytial virus (RSV) would have been avoided this fall/winter thanks to Beyfortusaccording to an estimate from Public Health France and the Pasteur Institute, published this Friday, April 26. This preventive treatmentproduced by the Sanofi-AstraZeneca alliance, was offered for the first time to all babies of the year last fall (subject to the number of doses available).
Several studies have already suggested that this Beyfortus had made it possible to protect babies, by around 80%, from serious forms of RSV infection (the virus which causes the vast majority of severe bronchiolitis).
In a new publication published this Friday, April 26, Public Health France also achieved an effectiveness of this order of magnitude against admissions to intensive care. But the novelty lies in another publication, carried out jointly with the Pasteur Institute and which should soon be published in a scientific journal.
One hospitalization avoided for 40 immunized children
The researchers based themselves on several data: number of hospitalizations for bronchiolitis, circulation of RSV in babies, doses delivered, etc. The peak in hospitalizations for RSV bronchiolitis was similar, among babies aged three months to two years who received very little treatment, this season compared to the previous one. On the other hand, it was half as high from one year to the next among toddlers under two years old, many of whom had been immunized. A sign that Beyfortus seems very effective.
After putting all this data through their modeling, the scientists therefore estimate that 5,800 hospitalizations of babies in the emergency room were avoided from September 15 to February 4, including 4,200 of infants under two months old. This represents a quarter of the total estimated in a “counter-factual” scenario, without the Beyfortus.
“When pediatric hospitals are saturated, we are bound to benefit from such a reduction in the number of hospitalizations. And the impact should be even greater if more children are immunized,” Simon Cauchemez, professor at the Pasteur Institute and lead author of the study, tells Le Parisien. Compared to the number of toddlers who received the treatment (more than 200,000), this result also corresponds to one hospital admission avoided for every 40 immunized children.
Soon a vaccine for pregnant women?
The impact would be even stronger if all hospitalizations were taken into account, not just those recorded after a trip to the emergency room. But be careful: this is only an estimate, based on a mathematical model subject to various methodological limits. Furthermore, we are only talking about RSV bronchiolitis here.
Other viruses can also cause this type of illness, without being able to expect any effectiveness from Beyfortus. “At the beginning, we worked on all bronchiolitis. But we noticed that some of them occurred when the VRS was not circulating,” describes Simon Cauchemez.
PODCAST. Bronchiolitis: how the drug Beyfortus was a victim of its success
More babies could receive this preventive treatment next year… provided the laboratory and health authorities agree on a number of doses and a purchase price, because demand has exceeded government expectations at last fall. But the Beyfortus will perhaps no longer be alone in this niche: the Pfizer vaccine aimed at protecting babies from RSV infections, intended for pregnant women, could hit the market in the coming months.
