Study shows: Hay fever nasal spray protects against SARS-CoV-2!

Study shows: Hay fever nasal spray protects against SARS-CoV-2!

Research on the anti-allergy nasal spray azelastine shows promising results in the prevention of COVID-19. In a current clinical study, a team from Saarland University has proven that the anti-allergic nasal spray with the active ingredient azelastine can significantly reduce the risk of SARS-CoV-2 infections. These results were published in the renowned specialist journal JAMA Internal Medicine published.

The randomized, double-blind and placebo-controlled study included 450 healthy participants. These were divided into two groups: 227 people received azelastine nasal spray three times a day for 56 days, while 223 participants took a placebo. The results are remarkable: In the azelastine group, only 2.2 percent became infected, while in the control group the infection rate was 6.7 percent. The infections were confirmed using PCR tests.

Results and implications of the study

In addition to the lower infection rate, the azelastine group also showed less symptomatic SARS-CoV-2 progression and a lower number of respiratory infections. Only 1.8 percent of the participants in the azelastine group were infected with rhinovirus, while 6.3 percent in the control group were affected. These results support previous in vitro studies demonstrating antioxidant effects of azelastine against SARS-CoV-2 and other respiratory viruses.

Professor Bals, one of the lead researchers, said the results offer enormous potential for follow-up studies. He recommends the nasal spray especially for risk groups, during high incidence phases or when traveling. The nasal spray has been used for decades to treat allergic rhinitis and could now also play an important role in COVID-19 prevention.

Study background and methodology

The study, conducted from March 2023 to July 2024, aimed to determine the effectiveness and safety of azelastine in preventing SARS-CoV-2 infections. Participants were recruited from Saarland University Hospital and received either azelastine (0.1%) or a placebo. Main outcomes and secondary endpoints were collected to assess the true effectiveness of the nasal spray.

The incidence of PCR-confirmed SARS-CoV-2 infections was significantly lower in the azelastine group compared to the placebo group. Five cases (2.2%) were recorded in the azelastine group, while 15 cases (6.7%) occurred in the placebo group. This corresponds to an odds ratio of 0.31, which underlines the protective effect of the nasal spray. The study is considered the first to demonstrate the preventive protective effect of azelastine in a real application scenario.

The results of this study are not only of academic interest, but also demonstrate successful collaboration between academic research, industry and public health care in the Saarland region. Azelastine could therefore represent a valuable addition to existing methods of COVID-19 prevention.