Ribavirin nasal spray alleviates allergic rhinitis symptoms by clearing nasal commensal viruses

Allergic rhinitis (AR) affects 20-30% of the global population, presenting a significant health burden. While commensal bacteria are well-studied in health and disease, the role of commensal viruses, particularly in the nose, remains largely unexplored. Current AR treatments often focus on symptom management or allergen avoidance, but this research investigates a novel pathogenic mechanism: the contribution of nasal commensal viruses. Understanding this overlooked viral component could unlock new therapeutic avenues beyond conventional antihistamines and corticosteroids.

Researchers conducted a randomized, double-blind, placebo-controlled, phase 2 clinical trial (ChiCTR2400082642) to assess the efficacy and safety of ribavirin spray in treating AR patients. The study aimed to determine if clearing nasal commensal viruses could alleviate AR symptoms. Patients were assigned to either the ribavirin spray group or a placebo group. The primary endpoints included changes in nasal commensal virus load and the severity of AR symptoms. The trial design ensured rigorous evaluation of the intervention's impact against a control, providing robust evidence for its therapeutic potential.

The study identified that nasal commensal viruses contribute to AR pathogenesis. Mechanistically, these viruses are recognized by innate sensors, initiating type I interferon production. This leads to the recruitment and generation of interferon-induced neutrophils in the nasal cavity, which subsequently release neutrophil extracellular traps (NETs) to promote AR. Most importantly, in the phase 2 clinical trial, patients receiving ribavirin spray experienced significantly reduced nasal commensal viruses and alleviated AR symptoms compared to the placebo group. This direct clinical evidence confirms the therapeutic efficacy of ribavirin spray. While specific quantitative data (e.g., exact percentages of reduction or p-values) were not provided in the abstract, the findings were described as 'significantly reduced' and 'alleviated symptoms'.