#18,194
Although it is not the usual fare for this blog, with rising COVID rates this summer and the fall flu season not far behind, we have a timely study out of the UK - published in The Lancet Respiratory Medicine Journal - on the impact of using saline nasal sprays in reducing respiratory infections.
It is important to note we are talking OTC saline sprays, not decongestants, antihistamines, corticosteroids, or other medications.
This study was funded by the UK's NIHR (National Institute for Health Research), which recently described the results in the following article:
Nasal sprays reduce symptoms and duration of colds and flu
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:
Patients were put into one of three treatment groups:
- 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
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.
- 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 results(Continue . . . )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.
- All the groups experienced a reduction in the number of days with severe symptoms - down by 25%
- antibiotic use - down by 25%
The Summary and link to the full study in the Lancet follows:
Nasal sprays and behavioural interventions compared with usual care for acute respiratory illness in primary care: a randomised, controlled, open-label, parallel-group trial
lProf Paul Little, FMedSci, Jane Vennik, PhD, Kate Rumsby, MSc, Prof Beth Stuart, PhD, Taeko Becque, PhD, Prof Michael Moore, BMedSci et al.
Open Access Published: July 11, 2024 DOI:https://doi.org/10.1016/S2213-2600(24)00140-1
Summary
Background
A small amount of evidence suggests that nasal sprays, or physical activity and stress management, could shorten the duration of respiratory infections. This study aimed to assess the effect of nasal sprays or a behavioural intervention promoting physical activity and stress management on respiratory illnesses, compared with usual care.
Methods
This randomised, controlled, open-label, parallel-group trial was done at 332 general practitioner practices in the UK. Eligible adults (aged ≥18 years) had at least one comorbidity or risk factor increasing their risk of adverse outcomes due to respiratory illness (eg, immune compromise due to serious illness or medication; heart disease; asthma or lung disease; diabetes; mild hepatic impairment; stroke or severe neurological problem; obesity [BMI ≥30 kg/m2]; or age ≥65 years) or at least three self-reported respiratory tract infections in a normal year (ie, any year before the COVID-19 pandemic).
Participants were randomly assigned (1:1:1:1) using a computerised system to: usual care (brief advice about managing illness); gel-based spray (two sprays per nostril at the first sign of an infection or after potential exposure to infection, up to 6 times per day); saline spray (two sprays per nostril at the first sign of an infection or after potential exposure to infection, up to 6 times per day); or a brief behavioural intervention in which participants were given access to a website promoting physical activity and stress management.
The study was partially masked: neither investigators nor medical staff were aware of treatment allocation, and investigators who did the statistical analysis were unaware of treatment allocation. The sprays were relabelled to maintain participant masking. Outcomes were assessed using data from participants' completed monthly surveys and a survey at 6 months.
The primary outcome was total number of days of illness due to self-reported respiratory tract illnesses (coughs, colds, sore throat, sinus or ear infections, influenza, or COVID-19) in the previous 6 months, assessed in the modified intention-to-treat population, which included all randomly assigned participants who had primary outcome data available. Key secondary outcomes were possible harms, including headache or facial pain, and antibiotic use, assessed in all randomly assigned participants. This trial was registered with ISRCTN, 17936080, and is closed to recruitment.
Findings
Between Dec 12, 2020, and April 7, 2023, of 19 475 individuals screened for eligibility, 13 799 participants were randomly assigned to usual care (n=3451), gel-based nasal spray (n=3448), saline nasal spray (n=3450), or the digital intervention promoting physical activity and stress management (n=3450). 11 612 participants had complete data for the primary outcome and were included in the primary outcome analysis (usual care group, n=2983; gel-based spray group, n=2935; saline spray group, n=2967; behavioural website group, n=2727).Compared with participants in the usual care group, who had a mean of 8·2 (SD 16·1) days of illness, the number of days of illness was significantly lower in the gel-based spray group (mean 6·5 days [SD 12·8]; adjusted incidence rate ratio [IRR] 0·82 [99% CI 0·76–0·90]; p<0·0001) and the saline spray group (6·4 days [12·4]; 0·81 [0·74–0·88]; p<0·0001), but not in the group allocated to the behavioural website (7·4 days [14·7]; 0·97 [0·89–1·06]; p=0·46).The most common adverse event was headache or sinus pain in the gel-based group: 123 (4·8%) of 2556 participants in the usual care group; 199 (7·8%) of 2498 participants in the gel-based group (risk ratio 1·61 [95% CI 1·30–1·99]; p<0·0001); 101 (4·5%) of 2377 participants in the saline group (0·81 [0·63–1·05]; p=0·11); and 101 (4·5%) of 2091 participants in the behavioural intervention group (0·95 [0·74–1·22]; p=0·69).Compared with usual care, antibiotic use was lower for all interventions: IRR 0·65 (95% CI 0·50–0·84; p=0·001) for the gel-based spray group; 0·69 (0·45–0·88; p=0·003) for the saline spray group; and 0·74 (0·57–0·94; p=0·02) for the behavioural website group.
Interpretation
Advice to use either nasal spray reduced illness duration and both sprays and the behavioural website reduced antibiotic use. Future research should aim to address the impact of the widespread implementation of these simple interventions.
Funding
National Institute for Health and Care Research
Note: For those who prefer using a neti pot and mixing their own saline solution, it is important to only use distilled, boiled, or sterilized water (see Neti Pots & Naegleria Fowleri).
While saline irrigation might not be a the total solution during respiratory virus season, it can certainly be used as an adjunct to other precautions.
