Azelastine nasal spray may prevent COVID-19, trial finds
In a phase 2 industry trial of healthy, vaccinated patients tested twice a week for SARS-CoV-2, thrice-daily intranasal azelastine reduced the COVID-19 infection rate by 67% compared with placebo. Rhinovirus infections were also reduced.
Azelastine nasal spray was associated with reduced risk of SARS-CoV-2 respiratory infections, a randomized industry trial in Germany found.
Researchers carried out the double-blind phase 2 trial in Germany between March 2023 and July 2024. A total of 450 participants (mean age, 33 years; 66.4% women) were randomly assigned to receive azelastine, 0.1%, nasal spray (n=227) or placebo (n=223) three times daily for 56 days. Participants underwent SARS-CoV-2 rapid antigen testing twice weekly, and positive results were confirmed by polymerase chain reaction (PCR). Almost all participants had been vaccinated at least once against COVID-19 (99.1%), with a median of three vaccinations and a median of 672 days since last vaccination. The trial was funded and designed by URSAPHARM Arzneimittel GmbH, a German pharmaceutical company. Findings were published by JAMA Internal Medicine on Sept. 2.
Incidence of PCR-confirmed SARS-CoV-2 infection in the intention-to-treat population was significantly lower in the azelastine group than in the placebo group (2.2% vs. 6.7%; odds ratio, 0.31 [95% CI, 0.11 to 0.87]; P=0.02). Azelastine was also associated with an increase in average time to SARS-CoV-2 infection among infected participants (31.2 vs 19.5 days), a reduction of the overall number of PCR-confirmed symptomatic infections (21 of 227 participants vs. 49 of 223 participants), and a lower incidence of PCR-confirmed rhinovirus infections (1.8% vs. 6.3%). Incidence of adverse events was similar between groups, with bitter taste, nosebleeds, and tiredness the most commonly reported.
Limitations include a relatively small sample size and low incidence of infections from certain pathogens. The study was also conducted in a mostly healthy vaccinated population, potentially limiting the generalizability of findings.
“The established safety profile, over-the-counter availability, and ease of use of azelastine nasal spray support its potential as a practical, scalable on demand approach to preexposure prophylaxis, particularly in high-risk settings such as large gatherings or travel,” the authors wrote. Larger trials are needed to confirm efficacy and explore benefits across more diverse populations, they added.
An accompanying editorial echoed the call for more research. “Future trials should include populations with risk factors for severe COVID-19, as these populations would benefit the most from new safe and effective prophylactic modalities,” the editorialists concluded.