A common over-the-counter nasal spray used to treat seasonal allergies might offer an unexpected benefit—helping to block Covid infections. That’s according to a new clinical trial from Saarland University Hospital in Germany, which found that azelastine, an antihistamine, lowered Covid risk significantly in a test group of healthy adults.
The Surprising Findings
Researchers gave 450 adults either azelastine spray or a placebo, instructing both groups to use it three times daily and test for Covid twice a week for nearly two months. In the end, only 2.2 percent of the azelastine group tested positive for Covid, compared to 6.7 percent in the placebo group. The spray also appeared to reduce the rate of other respiratory illnesses like flu.
What’s behind the surprising antiviral effect? Scientists aren’t completely sure. Theories include the spray binding to viruses in the nasal lining to block entry or interfering with the ACE2 receptor that Covid uses to infiltrate cells.
Should You Use It?
NBC News reported that Dr. Robert Bals, the lead author, said azelastine shows promise as a “scalable, over-the-counter prophylactic” in high-risk settings like travel or crowded events. But he also cautioned that more research is needed—especially on older and immunocompromised populations—before recommending it as a mainstream preventive tool.
Critics like Dr. William Messer noted that the thrice-daily routine may not be practical long-term. “A mask might be easier to comply with than remembering a nasal spray multiple times a day,” he said.
Related: A Popular Allergy Pill Is Linked to Higher Dementia Risk
What Experts Are Saying
While not a silver bullet, experts agree the trial adds evidence that the nasal lining could be a game-changing target for future vaccines. Dr. Peter Chin-Hong said the findings underscore the need for more mucosal vaccines that block infection at the entry point—not just serious illness later.
Related: How to tell if you have allergies or a cold
Key Takeaways
- Azelastine reduced Covid infections by nearly 70% in the study group.
- The spray is OTC, commonly used for seasonal allergies.
- Scientists theorize it blocks the virus in the nasal lining or disrupts cell entry.
- Experts say it’s not a vaccine substitute—but it might help in high-risk situations.
- Compliance matters: Using the spray three times daily could be a challenge.
