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

MDSpire News

Objective:

To evaluate the effect of ribavirin nasal spray on symptoms of allergic rhinitis by reducing nasal commensal viruses.

Approach:

Clinical Trial: A phase 2 randomized, double-blind, placebo-controlled trial involving 42 patients with allergic rhinitis, comparing ribavirin nasal spray (22 patients) to placebo (20 patients) over 4 weeks.
Laboratory Studies: Parallel studies in mouse models to investigate 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 the placebo group showed no significant change.
No serious adverse events or adverse drug reactions were reported.
Higher nasal commensal virus abundance correlated with symptom severity and interferon-stimulated gene expression.

Interpretation:

The findings suggest that reducing nasal commensal viruses may improve allergic rhinitis symptoms, although further research is needed.

Limitations:

The study was small and conducted at a single center, necessitating larger multicenter phase 3 trials for confirmation.
Mechanistic evidence primarily 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.