Nasal Sprays & Mouthwashes: New Allies in the Fight Against Respiratory Viruses
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As of October 7th, 2025, researchers are increasingly focused on the potential of nasal sprays and mouthwashes as supplementary tools to combat respiratory viruses, including SARS-CoV-2, alongside vaccination and customary protective measures.
Coronaviruses and other pathogens initially invade the body through the delicate mucous membranes lining the mouth, nose, and throat.While vaccination remains the cornerstone of defense, scientists are exploring innovative ways to intercept thes viruses before they establish a deeper infection. Nasal sprays and mouthwashes are emerging as promising additions to our arsenal, particularly during periods of high transmission, for individuals in high-risk groups, or when traveling.
Azelastine Nasal Spray: Promising Early Results
Recent attention has focused on azelastine, a well-established antihistamine, for its antiviral properties. Laboratory studies have demonstrated its ability to neutralize viruses like SARS-CoV-2 and other common cold viruses.A study conducted at the University of Saarbrücken, in collaboration with a pharmaceutical company, investigated the efficacy of azelastine nasal spray in a human population.
The research, involving nearly 500 participants divided into treatment and placebo groups, revealed a meaningful reduction in infection rates. “The nasal spray was shown to prevent two thirds of infections,” according to study findings. Specifically, only five participants in the azelastine group contracted the virus, compared to 15 in the placebo group. Moreover,those who did become infected despite using the spray experienced a milder course of illness. While these results are encouraging,researchers emphasize the need for larger-scale studies to confirm the findings and fully understand the mechanism of action.
Azelastine isn’t the only nasal spray showing promise. Several novel formulations are under development, employing different antiviral strategies. some utilize antiviral filters, while others leverage molecular binding mechanisms to prevent viral entry.
One approach involves sprays containing carrageenan (carragelose), a substance derived from red algae. This compound works by creating an electrostatic barrier that prevents viruses from attaching to receptors on mucous membrane cells, effectively blocking infection. Another utilizes hydroxypropylmethylcellulose (HPMC), a modified cellulose that forms a protective film, encapsulating viruses and facilitating their removal when blowing your nose.
Newer sprays combine HPMC with nitric oxide and citric acid. The citric acid alters the pH level in the nasal passages, creating an unfavorable environm
Masks and Protection: A Reminder
- In a scenario with no masks at a distance of 1.5 meters, infection occurred within three minutes.
- With the infectious person unmasked and the susceptible person wearing a well-fitting FFP2 mask, the risk of infection considerably decreased.
- When both individuals wore well-fitting FFP2 masks at a distance of 1.5 meters, the risk of infection was minimized, even over extended periods.
These findings reinforce the message that a properly fitted mask provides ample protection, and combining mask use with vaccination offers the highest level of defense.
Expert Perspectives
The research into these preventative measures draws on expertise from leading institutions:
- Hannover Medical School: Contributing to the understanding of viral transmission and prevention strategies.
- Pharmacy management at the University Hospital Hamburg-Eppendorf: Providing insights into the pharmaceutical aspects of nasal and oral hygiene.
- Director of the Department of Internal Medicine V – pulmonology, Allergology, Respiratory and Environmental Medicine, Saarland University Hospital, Homburg: Leading research on respiratory viruses and their impact on the body.
As we continue to navigate the evolving landscape of respiratory viruses, these emerging strategies – alongside established preventative measures – offer a multi-faceted approach to protecting public health.
