Roll-out of 'Germ Defence' website through GP practices to help reduce coronavirus infections

Research team

University of Bristol: Jeremy Horwood, Melanie Chalder, Pippa Craggs, Sarah Denford, Rachel Denholm, Frank de Vocht, Martha Elwenspoek, John Macleod, Cathy Rice, Jonathan Sterne, Lucy Yardley. University of Bath: Ben Ainsworth. University of Southampton: James Denison-Day, Paul Little, Sascha Miller, Michael Moore, Kate Morton, Beth Stuart, Lauren Towler, Merlin Willcox, Lucy Yardley.

Person washing hands at sink under tap with lots of soap

About the project 

Germ Defence is an evidence-based, behaviour change website that provides practical advice on how to reduce the spread of infection in the home. In a previous randomised controlled trial of more than 20,000 households (Little et al., 2015), Germ Defence proved successful in reducing the spread of seasonal and swine 'flu, and helped reduce the risk of respiratory infection by around 14%. It also reduced the number of primary care consultations and antibiotic prescriptions needed by people who used the website. Germ Defence has recently been updated for use during the coronavirus pandemic.

Researchers at the Universities of Bristol, Bath and Southampton have received funding from UK Research and Innovation (UKRI) and the National Institute for Health Research (NIHR) to evaluate how effective the website is in reducing coronavirus infection. They will work with GP practices in England, who will be asked to send the Germ Defence website link to their patients.

Chris Whitty, the Chief Medical Officer (CMO) for England, has endorsed this as a national priority project and it has been adopted by the National Institute of Health Research, Clinical Research Network (NIHR CRN) as an Urgent Public Health Covid-19 Portfolio Study.

The updated coronavirus version of Germ Defence helps users think about when and how to carry out key infection control behaviours such as hand washing and cleaning, avoiding sharing rooms and surfaces, managing incoming deliveries, and ventilating rooms. It draws on behaviour change techniques to help users think through and adopt better home hygiene habits and problem solve any barriers.

A series of questions on the website take around 10 minutes to complete, but the answers allow the tailoring of advice for people’s personal circumstances and are designed to make a lasting and lifetime impact. The website has been translated into over 20 languages.

Project aims

The updated Germ Defence website could help prevent a wave of coronavirus and flu during this Autumn and Winter, as we know that coronavirus is caught in the same way as other viruses. Although Germ Defence has been updated to be relevant to coronavirus, it has not yet been proven to be effective in reducing coronavirus infections. The aim of this project is to test how effective the new Germ Defence website is.

What we will do

Half of the GP practices in England will be randomly chosen and asked to immediately send out the Germ Defence website link to their patients in the Autumn of 2020. The other half of the practices will be contacted to send out the Germ Defence website link in February 2021. The researchers will examine the effects of the Germ Defence website on rates of respiratory infection (including coronavirus and seasonal flu), and whether it reduces healthcare use (including number of GP consultations, antibiotic prescriptions, and hospital admissions) in each of the two randomly assigned groups.

GP practices will not be required to send the research team any information. After they have sent the unique website link to their patients, the researchers will know whether patients use the Germ Defence website from anonymous data produced by the website. The data will tell the research team if any patients from each practice have used the website but it will not record who these patients are.

The research team will also use anonymised NHS data, that is collected nationally as part of routine care, to compare whether infection rates and use of health care services is lower in practices that sent Germ Defence information to their patients immediately, compared to those that sent the information later.

Anticipated impacts

The previous trial showed that people who followed Germ Defence advice got fewer and less severe infections and so did the people they live with. If the updated Germ Defence website helps prevent infections, including coronavirus infections, it could help save lives by reducing the spread of the virus and may prevent a wave of coronavirus and 'flu during this Autumn and Winter. By reducing the number of infections and use of health care services, this could increase the capability and capacity of the NHS to cope with the number of patients using it.

Further information

The trial is being led by National Institute for Health Research, Applied Research Collaboration West (NIHR ARC West) and is a collaboration between the Universities of Bristol, Bath and Southampton.

GP practices will not receive any financial reimbursement for taking part in the trial. Practices will instead be credited with one recruit when they send the link to the Germ Defence website to their patients. This will count towards research activity for the Research Sites Initiative (RSI) scheme.

Ethics approval for the study was obtained from the NHS Health Research Authority (HRA) Yorkshire & The Humber - Leeds West Research Ethics Committee (REC) (reference: 20/YH/0261).


The project is funded by the UK Research and Innovation (UKRI) Coronavirus Rapid Response Call and NIHR ARC West and the NIHR Health Protection Research Unit in Behavioural Science and Evaluation at University of Bristol and is supported by Health Data Research UK (HDR UKBetter Care South-West Partnership and the University of Bristol’s Centre for Academic Primary Care.