Belgian researchers working with Danish partners report that respiratory syncytial virus (RSV) infections in early infancy are linked to a higher risk of childhood asthma, especially in children with a genetic tendency to allergies. In experimental models, protecting newborns from RSV prevented the immune changes associated with later asthma. The findings, published in Science Immunology, highlight potential long-term benefits of emerging RSV prevention tools.
Researchers from VIB and Ghent University (UGent) in Belgium, working with partners in Denmark, combined nationwide Danish health registry data with controlled laboratory studies to examine how early-life RSV infections might influence asthma risk later in childhood. Their analysis found that infection with RSV in early infancy was strongly associated with a higher likelihood of developing asthma, particularly in children with a family history of allergies or asthma, according to a summary from the Vlaams Instituut voor Biotechnologie.
The team reports that severe RSV infections in the first months of life can skew the developing immune system toward exaggerated responses to everyday allergens, including house dust mites. This effect appears to be amplified when asthma or allergy runs in the family, as allergen-specific antibodies passed from parents to their newborns can further increase sensitivity. The study describes a mechanism in which maternal allergy and neonatal RSV infection act together via Fc receptor (FcR)-mediated allergen uptake to promote asthma development in early life.
The findings, published on November 28 in the journal Science Immunology, are set against the backdrop of childhood asthma affecting an estimated 5–15% of children across Europe, placing a substantial burden on families and health systems. “Childhood asthma is a complex disease with many contributing factors,” said Prof. Bart Lambrecht of the VIB-UGent Center for Inflammation Research, the study’s senior author. “We found that early-life RSV infection and genetic allergy risk interact in a very specific way that pushes the immune system toward asthma. The encouraging news is that this process can be prevented.”
In experimental models, the researchers showed that shielding newborns from RSV prevented these immune shifts from occurring and, in those models, asthma did not develop. “With RSV prevention now becoming widely accessible, we have an opportunity to improve long-term respiratory health, not just prevent RSV hospitalizations,” said Prof. Hamida Hammad of VIB-UGent, co-senior author of the study, as reported by VIB.
The authors note that maternal vaccination against RSV during the third trimester of pregnancy and passive immunization of newborns with long-acting monoclonal antibodies are already being rolled out in many countries, though uptake has so far been uneven. These tools have been shown in other studies to sharply reduce RSV-related hospitalizations in infants, and the new research suggests they might also confer longer-term benefits by lowering asthma risk.
“This is a moment where policy, science, and pediatricians can come together,” Lambrecht said. “If preventing RSV infection also reduces asthma risk, the benefits for families and health systems could be enormous.”
According to VIB, the research was supported by the European Research Council, Ghent University, and the Research Foundation – Flanders (FWO).
