The Immune Defence study: a randomised trial evaluating nasal sprays and behavioural intervention approaches to reduce respiratory infections in primary care

Conference:

SAPC ASM 2024 - Bristol

Talk Code:

1A.1

Presenter:

Paul Little

Co-authors:

Jane Vennik, Kate Rumsby, Taeko Becque, Nick Francis, Chistopher C. Butler, Alastair Hay, Lucy Yardley, Adam Geraghty

Author institutions:

University of Southampton, University of Oxford, Bristol University

Problem

Respiratory infection (RTI) are the major cause of winter pressure in the NHS. Limited evidence suggests that using common nasal sprays, or improving immune function through increasing physical activity and managing stress, could reduce respiratory infection (RTI) duration.

Approach

13799 participants, from 332 GP practices, aged >=18 years with a co-morbidity/risk factor for infection, and/or recurrent infection in a normal year (>=3 RTIs), were randomised by online software to: i) usual care (n=3451) ii) Vicks First-Defence nasal spray (n=3448) iii) saline nasal spray (n=3450) , or iv) a brief behavioural website promoting physical activity and stress management (n=3450).

Findings

. In 6 months 54% (1637/2994) of the usual care group had incident infections, reduced by the behavioural website (adjusted risk ratio (RR) 0.95 (0.91 to 0.99) but not the sprays (Vicks 0.98 (0.94 to 1.03), saline 0.98 (0.94 to 1.02)). The usual care group had a mean of 8 RTI illness days which was reduced in both spray groups (Vicks 6.5 days adjusted incident rate ratio (IRR) 0.82, 95% CI 0.77 to 0.88), Saline 6.4 days (IRR 0.81, 95% CI 0.76 to 0.87), behavioural website 7.4 days (0.97, 95% CI 0.91 to 1.04)); for those reporting an infection it was 15,12,11.8 and 14 days respectively. All interventions reduced important harms - days of more severe symptoms and antibiotic courses - and both sprays reduced work days lost, but headache was more common with the Vicks spray (8% vs 4.8% usual care).

Consequences

Advice to use either nasal spray at the first sign of an RTI reduced illness duration, and a behavioural website reduced incident infections. All interventions reduced severe symptoms and antibiotic use. If widely used these interventions could potentially improve antimicrobial stewardship, and reduce the impact of respiratory viruses for patients, the health service and the wider economy.

Submitted by:

Paul Little

Funding acknowledgement:

This study is funded by the NIHR Programme Grants for Applied Research (RP-PG-0218-20005). The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care. LY is an NIHR Senior Investigator and her research programme is partly supported by NIHR Applied Research Collaboration (ARC)-West and NIHR Health Protection Research Unit (HPRU) for Behavioural Science and Evaluation.