May Clearing Nasal Viruses Improve Allergic Rhinitis?

A phase 2 randomized trial suggests reducing nasal commensal viruses with ribavirin spray may improve allergic rhinitis symptoms while supporting a proposed disease mechanism.

By
Andrea Surnit
July 7, 2026
4 min

Conexiant

Objective:

To investigate whether reducing nasal commensal viruses with ribavirin nasal spray can improve symptoms in patients with allergic rhinitis.

Approach:

Clinical Trial: A phase 2 randomized, double-blind, placebo-controlled trial involving 42 patients with allergic rhinitis, assigned to receive ribavirin nasal spray or placebo for 4 weeks.
Laboratory Studies: Parallel studies in mouse models to explore the biological effects of reducing nasal commensal viruses.

Key Findings:

Ribavirin treatment resulted in lower Total Nasal Symptom Scores compared to placebo after 4 weeks.
Improvements were also noted in Visual Analog Scale and Rhinitis Control Assessment Test scores.
Ribavirin reduced nasal commensal virus abundance, while viral abundance remained unchanged in the placebo group.
No serious adverse events were reported during the study.
Higher nasal commensal virus abundance correlated with symptom severity and interferon-stimulated gene expression.

Interpretation:

Limitations:

The study was small and conducted at a single center, requiring confirmation in larger, multicenter phase 3 trials.
Much of the mechanistic evidence was derived from mouse models.
Specific nasal commensal viruses identified have not been established as causal drivers of allergic rhinitis in humans.
Effectiveness and safety of ribavirin spray remain exploratory.