Widely available over-the-counter nasal sprays could help fend off upper respiratory tract infections such as colds, chest infections, flu, sore throat, and sinus infections, preventing the onset of severe symptoms. One of the largest trials to date, involving nearly 14,000 adults, has found these sprays can reduce the duration of illness by about 20 percent. They also decrease the number of days with severe symptoms, reduce time off work or normal activities, and lessen antibiotic use.
The study, led by the University of Southampton in collaboration with the University of Bristol and funded by the National Institute for Health and Care Research (NIHR), was published July 12, 2024, in The Lancet Respiratory Medicine.
Recent evidence suggests that using nasal sprays to wash out viruses from the nose and throat or enhancing immune function through increased exercise and stress management can reduce the frequency and severity of respiratory infections. To investigate further, researchers conducted a large-scale randomized trial comparing the effectiveness of two different types of nasal spray and an online resource offering advice on physical activity and stress management.
The study recruited 13,799 adult patients from 332 general practice clinics. All participants had an existing health issue or risk factor for infection, and/or a history of recurrent respiratory infections. Patients were randomized to receive one of three interventions: a Vicks First Defense gel-based nasal spray, which uses a microgel to trap and neutralize viruses in the nose; a saline liquid-based nasal spray, which reduces virus levels in the nasopharynx; or access to an online resource promoting physical activity and stress management.
All three interventions reduced antibiotic use by more than 25 percent and decreased the number of days with severe symptoms. Despite participants not using the sprays as frequently as instructed, both sprays reduced the overall duration of illness by around 20 percent and led to a 20-30 percent reduction in days lost from work or normal activities.
In comparison, the online advice on physical activity and stress management yielded a modest five percent reduction in infection incidence. However, this cost-effective option could have a significant population-level impact due to its ease of distribution.
Paul Little, Professor in Primary Care Research at the University of Southampton, who led the trial, stated, "Our results show nasal sprays are effective in reducing the duration and severity of respiratory infections and minimizing interference with normal activities. This is particularly important given the UK's regular winter infection surges. The reduction in antibiotic use is also crucial in combating antibiotic resistance, a major public health threat."
"Given these results, we advise those at higher risk of infections or those with recurrent infections to use a nasal spray at the first sign of cough, sore throat, cold, or flu-like symptoms to prevent full development. Sprays should also be used preventatively after close exposure to infected individuals," Little added.
