In a world-first clinical trial of the efficacy of masks, researchers found adult mask wearers* in the home were four times more likely than non-wearers to be protected against respiratory viruses, including the common cold.

The findings – published recently in Emerging Infectious Diseases, the journal of the US Centres for Disease Control and Prevention – have global implications and are particularly relevant to efforts to combat the spread of flu pandemics and other emerging respiratory diseases such as SARS.