For the first time, the United States observed a marked decline in infantile hospitalizations linked to the syncytial respiratory virus (VRS), thanks to two major innovations: the vaccine administered to pregnant women and the Nirsvimab, a protective antibody for babies. Promising results, confirmed by a CDC study and supported by the National Academy of Medicine, which call for rapid and generalized adoption.
The VRS, a silent danger for infants
The syncytial respiratory virus (VRS) is one of the main causes of hospitalization in toddlers, especially during their first months of life. Each winter, he highlights the pediatric services, causing bronchiolitis, respiratory distress and anxieties among young parents. Until 2023, few options existed to effectively protect infants. But two medical advances have changed the situation: a vaccine administered at the end of pregnancy, and the Nirsevimab, a monoclonal antibody injected directly to babies.
A recent study, published in the Morbidity and Mortality Weekly Report By American CDCs, reveals that these two combined approaches made it possible to reduce up to 52 % the hospitalizations due to the VRS in infants from 0 to 2 months during the winter 2024-2025. An unprecedented drop, all the more significant since the season was more virulent than the previous ones.
Encouraging data … and a strategy to generalize
The study is based on surveillance data from RSV-Net and NVSN, two networks covering dozens of counties in the United States. In infants under 7 months – main targets of prevention campaigns – hospitalizations fell from 28 to 43 %, according to areas. These figures climb up to 71 % when excluding regions where vaccination was introduced late, as in Houston.
Spectacular results which, even if they do not make it possible to establish a direct relationship (for lack of individual data), leave little doubt as to the effectiveness of prevention. Conversely, older children, unprotected, saw their hospitalization rates climb, confirming that these decreases are not due to a lower circulation of the virus, but to the protective effect of interventions.
In France, a call to catch up
The National Academy of Medicine, in a recent press release, alert on the low vaccination rate of pregnant women in France. Although prenatal vaccination against darling, flu, COVID-19-and now VRS-is recommended, less than a third of pregnant women are actually protected. In question: a lack of information, the absence of systematic prescription, and marked regional inequalities.
The Academy calls to integrate these vaccines in the prenatal care path, to train professionals, and to make vaccines available wherever future mothers are followed. Because protecting a newborn begins before birth. And the American data clearly show that they are worn early is to save hospitalizations – even lives.
The VRS vaccine administered during pregnancy, combined with Nirsevimab for infants, represents a major advance in the prevention of infantile respiratory diseases. The results observed in the United States are tangible proof of their effectiveness. In France, it is time to follow this example, by fully integrating these tools into pregnancy monitoring and strengthening confidence in prenatal vaccination. The health of toddlers depends on it.