Germ Defence

Germ Defence ( is a behaviour change website, based on scientific evidence, that gives practical advice on how to reduce the spread of infection in the home. In a randomised controlled trial in more than 20,000 households (Little et al., 2015), using Germ Defence reduced the spread of respiratory infections, and the number of GP visits and antibiotic prescriptions needed by people who used the website. The website has now been updated for use during the coronavirus pandemic.

Germ Defence helps people understand what measures to take and when to take them to avoid infection from coronavirus. This includes hand washing, hygiene and ventilating rooms. Using behaviour change techniques, it helps people think through and adopt better home hygiene habits and find ways to solve any barriers. This is especially important with the emergence of new variants that are more transmissible.

A series of questions on the website take around 10 minutes to answer. People then get tailored advice that fits their personal circumstances, designed to help them make lasting changes. The website has been translated into more than 20 languages.

What we will do

The Public Health Agency and the Department of Health are working with stakeholders to publicise the Northern Ireland Germ Defence website: Every person who uses the website will be invited to complete a short anonymous survey so that we can establish what people found helpful and what further improvements could be made to ensure that it is fit for purpose.

Anticipated impacts

The previous trial showed that people who used Germ Defence advice got fewer and less severe infections, as 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 reduce or prevent a wave of coronavirus and flu this autumn and winter. By reducing the number of infections and use of health care services, it could stop the HSC being overwhelmed at its busiest time.

Further information

The project is collaboration between the Behaviour Change Group which is a Public Health Agency Pandemic Response Cell and the designers of Germ Defence at Universities of Bristol, Bath and Southampton.

Ethics approval for the Northern Ireland project was given by Ulster University

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