OTC nasal spray seemed to cut COVID infections by 67% in mid-sized trial
Daily squirts of a safe, over-the-counter allergy nasal spray may prevent COVID-19 infections from taking hold, according to results published Tuesday in JAMA Internal Medicine. In a mid-staged trial, the spray appeared to reduce infections by promising 67 percent, though a larger trial will need to confirm that robust efficacy.
The trial was a randomized, double-blind, placebo-controlled Phase 2 trial conducted by researchers at Germany's Saarland University between March 2023 and July 2024. The study included 450 healthy adults, about half of whom (227) spritzed their noses three times a day with the generic antihistamine nasal spray, azelastine, which can be purchased over the counter in the US. The placebo, meanwhile, was a spray with an identical composition except for the absence of the antihistamine. The two groups had similar mixes of previous COVID-19 vaccination and infection statuses.
After about 56 days of frequent mistings, only five people using the allergy spray (2.2 percent) caught a SARS-CoV-2 infection, while 15 people using a placebo (6.7 percent) got the pandemic infection. That 4.5 percentage-point drop represents a 67 percent reduction in COVID-19 cases, though the numbers here are small. Still, the researchers noted that the five people using the allergy spray who contracted COVID-19 took more time to get the infection than the 15 in the placebo group (31 days versus 19.5). This could hint that the spray held off some infections from exposures early in the trial. And when the allergy spray users did get COVID-19, they were positive on a rapid antigen test for less time than those infected in the placebo group (3.4 days versus 5.1 days), suggesting they cleared the virus a bit faster.