Severe respiratory syncytial virus (RSV) infections in infancy combined with maternal allergy dramatically increase one’s risk of developing asthma later in life. Researchers in Denmark uncovered staggering statistics in their study, “Maternal Allergy and Neonatal RSV Infection Synergize Via FcR-Mediated Allergen Uptake to Promote the Development of Asthma in Early Life.”
In analyzing 1.5 million children, researchers found that infants hospitalized for RSV bronchiolitis within the first six months of life were three times more likely to develop asthma. When combined with maternal asthma or allergic rhinitis, the risk surged more than fivefold. Their results were published in Science Immunology.
The study included decades of registry-based follow-up and explored the biological mechanism behind this link using a preclinical mouse model. Neonatal viral infection was shown to upregulate Fc receptors on dendritic cells, enabling these immune cells to capture allergens more efficiently when maternal allergen-specific antibodies are present. This process amplifies type 2 inflammation and primes T helper 2 (TH2) cells, which are hallmarks of allergic asthma.
The research also demonstrated that RSV immunoprophylaxis — the process of stimulating long-acting RSV-neutralizing antibodies during the perinatal period — prevented asthma-like pathology in mice. These findings suggest that preventing severe RSV infections in early life could not only reduce hospitalizations but also lower long-term asthma incidence.
According to the study’s authors, RSV carries one of the highest population-attributable fractions for asthma. Key data show that perinatal prevention strategies could have profound benefits, especially for children born to allergic parents, they noted.
The study underscores the importance of maternal vaccination and newborn immunoprophylaxis programs now being rolled out globally, offering hope for reducing the burden of chronic respiratory disease.
