Published: 12 July 2024
An NIHR-funded study has found that over-the-counter nasal sprays are effective at reducing the symptoms and duration of flu and colds in at-risk patients. They could also reduce antibiotic use.
Large-scale randomised trial
There is some evidence to show that using nasal sprays could reduce the frequency and severity of respiratory infections. Improving immunity through exercise and managing stress may also help. To investigate this, researchers ran a large-scale randomised trial to compare these treatments. They investigated two different types of nasal spray and an online resource providing advice on physical activity and stress management.
Researchers recruited 13,799 adult patients from 332 GP practices. The patients all had existing health problems or risk factors for infection, such as:
- two existing health problems, for example asthma and heart disease or obesity
- a compromised immune system, due to serious illness or medication
- experience of recurrent respiratory infections in the past
Patients were put into one of three treatment groups:
- Vicks First Defence gel-based nasal spray - a microgel that traps viruses
- a saline nasal spray - a mixture of salt and water that reduces levels of virus
- an online resource promoting physical activity and stress management
The adults in the nasal spray groups were asked to use the nasal spray six times a day after they experienced the early symptoms of a cold.
The results
All the groups experienced a reduction in
- the number of days with severe symptoms - down by 25%
- antibiotic use - down by 25%
However, nasal sprays were more effective at speeding up recovery times. Both nasal sprays shortened the duration of the illness by 20% which resulted in a 20-30% reduction in days off from work. The exercise and stress reduction group experienced 5% reduction in symptoms.
Reducing pressure on the NHS
All of the interventions have the potential to reduce pressure on the health service during the winter and reduce the use of antibiotics. Online exercise and stress management advice could be a cost-effective way to reduce the impact of cold and flu viruses in the UK.
During the study not everyone managed to follow the instructions exactly. Researchers suspect the effectiveness of these interventions could be much higher if the instructions were followed.
Paul Little, Professor in Primary Care Research from the University of Southampton, who led the trial, said: “Our results show nasal sprays work extremely well to reduce the duration and severity of respiratory infections, and interference with normal activities, which is particularly important in light of the winter infection surge the UK regularly experiences. The finding of a reduction in the use of antibiotics is also potentially very important in the fight against antibiotic resistance, one of the major public health threats of our time. Given these results, our advice to people is if possible, at the first sign of cough, sore throat, cold or flu like symptoms, use a nasal spray, to prevent it from developing.”
Lucy Yardley, OBE, Professor of Health Psychology at the University of Bristol and University of Southampton, who led the nasal spray part of the study, added: “Our analysis suggests that the benefits were even greater when people used the sprays more often - we advised six times a day at the first sign of a cold - but many people in the study did not use the spray that often.”
The research was published in The Lancet Respiratory Medicine journal, and was led by the University of Southampton in collaboration with the University of Bristol.
The study was funded by NIHR Programme Grants for Applied Research with support from NIHR Health Protection Research Unit (HPRU) in Behavioural Science and Evaluation and NIHR Applied Research Collaboration West (ARC West).
A short version of the guidance given to people in the study is being made freely available online: https://immunedefence.lifeguide.site/