Can a Simple Nasal Spray Keep You Healthier This Winter?
Azelastine, long used for allergies, shows antiviral promise in preventing colds and COVID-19.
If you could reduce your chances of catching COVID-19 or even the common cold by adding a quick nasal spray to your daily routine, would you do it? For many readers, especially during travel or the winter surge, the answer is a cautious yes, with one condition: it needs to be safe, affordable, and actually work.
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A new randomized, placebo-controlled trial suggests that Azelastine, a well-known antihistamine nasal spray, may meet these criteria when used regularly as a preventive measure (link to published study here).
Azelastine has been on pharmacy shelves for decades to treat allergic rhinitis; what’s new is evidence pointing to antiviral effects at the site that matters most - the nasal lining, where respiratory viruses first take hold.
In a study of 450 healthy adults in Germany, participants who used Azelastine nasal spray three times daily for eight weeks had significantly fewer PCR-confirmed COVID-19 infections than those who used a placebo spray: 2.2% versus 6.7%. Those who did get infected on Azelastine tended to get infected later and had shorter periods of positive rapid tests. They also had fewer symptomatic cases.
What stands out is that this trial didn’t ask people to live in a bubble; it measured what happened during everyday life, work, school, and commutes. While no single intervention is a silver bullet, this may be the kind of practical, additive tool many families would like to see.
How does an allergy spray fight viruses?
Azelastine is more than an antihistamine; in lab studies, it interacts with several pathways that viruses use to enter cells and replicate. These include the ACE2 receptor (which SARS-CoV-2 uses to dock), the viral main protease (Mpro), and the σ-1 receptor, as well as effects that suppress ICAM-1, a door that rhinoviruses often use.
None of these pathways alone explains everything, and the authors are careful to say that a single “pan-viral” mechanism for infection hasn’t been established. The most plausible explanation is a combination of direct antiviral actions and dampening of the inflammatory “hospitality” that makes the nasal lining more permissive to infection.
The nose is also the right “address”. Most respiratory viruses begin by colonizing and replicating in the upper airway; that’s why a well-timed, locally active medication can have outsized effects, mainly when used consistently through an exposure period. In this study, the baseline schedule was three times daily, with a practical “booster” option - five times a day for three days (if someone developed symptoms, had a known exposure, or a household contact tested positive).
Pharmacometric modeling supports the idea that more frequent dosing raises local drug levels and improves viral suppression at the mucosa.
What did the study find?
Here are the most significant takeaways:
Fewer COVID-19 infections: 2.2% with Azelastine vs 6.7% with placebo over 56 days; odds ratio 0.31 and statistically significant.
Less symptomatic illness: Symptomatic PCR-confirmed COVID-19 occurred in 1.8% vs 6.3%.
Shorter positive-test duration: On average, participants on Azelastine had about 1.7 fewer days of lab positivity if they did get infected, suggesting quicker viral clearance or lower viral burden.
Fewer total respiratory infections: There were fewer lab-confirmed infections of any kind in the azelastine group (21 vs 49), and fewer participants with at least one lab-confirmed infection (8.4% vs 18.8%).
Rhinovirus reduction: The spray group had fewer PCR-confirmed rhinovirus infections, aligning with Azelastine’s effects on ICAM-1 biology in the nose.
How safe is it?
Reasonably good overall and consistent with decades of clinical use. The most common nuisance is a bitter taste. Nosebleeds occurred in a small minority; a few participants reported tiredness, and discontinuations were rare, with no serious events attributed to the spray. The placebo group also experienced frequent mild events. Remember, any nasal spray can irritate. Still, the trend shows that Azelastine has more treatment-related, mostly mild side effects, which align with what allergy patients report in everyday life.
What this is and is not?
This rigorously conducted, placebo-controlled trial shows that a simple, accessible intervention reduced confirmed COVID-19 infections and overall lab-confirmed respiratory infections over two months of regular daily exposure in healthy, mostly vaccinated adults.
It’s not a vaccine replacement, and it’s not a guarantee; it’s a local defense at the point of viral entry that can stack with the basics you already know. Keep vaccinations up to date, improve indoor air (ventilation and filtration), consider situational masking, and stay home when sick.
Who may consider using it (after consulting your doctor)?
People with frequent unavoidable exposures during peak season for respiratory infections: teachers, clinicians, retail and hospitality workers, frequent flyers; anyone whose life places them shoulder-to-shoulder with others most days.
Households with vulnerable members - older adults, people who are immunocompromised, or those with chronic lung or heart conditions may benefit from extra precautions during surge periods. However, direct evidence in high-risk groups awaits larger, multicenter studies.
Travelers and event goers: the study’s optional short-term “boost” strategy (five times daily around a high-risk window) is an intuitive, low-cost way to add protection during holidays, conferences, concerts, or long-haul flights.
How to use it, like in the study (talk to your doctor first)?
Dose: One spray per nostril, three times daily, using a 0.1% azelastine formulation (1 mg/mL), which corresponds to many OTC products; check labels to confirm the concentration.
On-demand escalations: Consider five times daily for three days if you develop symptoms, have a known exposure, or someone in your household tests positive. This mirrors the study protocol and the pharmacokinetic rationale for higher local exposure when risk is temporarily elevated.
Expect mild side effects: A bitter taste is typical, and nosebleeds can occur. If you’re sensitive, try rinsing your mouth after use and aim the nozzle slightly outward from the septum to reduce irritation.
Caveats to keep in mind
This is one center study with modest numbers. While the results are statistically significant for the primary endpoint, larger, multicenter trials are needed to confirm efficacy and understand performance across different ages and viral landscapes.
Potential unblinding: That bitter taste could tip participants off influencing behavior or symptom reporting; however, the placebo contained hypromellose, which itself may offer minor barrier effects, making this less likely to overestimate benefit.
Testing limitations: Twice-weekly RAT (rapid antigen screen) with PCR confirmation was a robust testing protocol but not perfect; some asymptomatic, brief infections could have been missed.
Although Azelastine is an over-the-counter medication available without a prescription, it has never been evaluated or approved by the FDA for preventing respiratory virus infections.
The bigger picture for wellness and longevity
From a healthspan perspective, fewer respiratory infections means fewer missed workouts, fewer inflammatory hits to the system, and less disruption to routines that protect long-term health, sleep, nutrition, movement, and social engagement.
Interventions that are safe, affordable, and easy to adopt tend to be the ones people sustain; Azelastine may fit that profile, especially when framed as part of a broader “mucosal hygiene” habit during viral season.
Azelastine nasal spray is a practical, well-tolerated option that lowered confirmed COVID-19 infections and overall lab-confirmed respiratory infections in this randomized trial, with signals of benefit against rhinovirus as well.
If your doctor approves, consider it only as an adjunct during higher-risk months and events, particularly if you value minimizing illness days or protecting vulnerable loved ones.
Please keep in mind that confirmation from larger, diverse studies is still needed before calling it definitive. As always, integrate it with other measures: stay current on vaccines, improve indoor air quality, and tailor your personal risks to your values and responsibilities.