Sydney, April 28 (Inditop) Donning a face-mask is an easy way to protect oneself from severe respiratory illnesses like swine flu when vaccines are unavailable or in short supply, according to a study.

In the first ever clinical trial of the efficacy of masks, researchers found adult mask wearers at home were four times more likely than non-wearers to be protected against a range of respiratory viruses, including influenza, SARS and even the common cold.

The findings have global implications and are particularly relevant for efforts to combat flu pandemics such as the latest outbreak of swine flu.

“In the event of a severe pandemic, demand for protection could become a law and order issue,” said study co-author, Raina MacIntyre, professor of infectious diseases at the University of New South Wales (UNSW).

“In a crisis, vaccine development is likely to be delayed and drugs may be in short supply or not available at all,” she said.

“Limited supplies will be directed first to front line health workers, so masks are an important means of protection for the community, who otherwise may be last in line for vaccines and drugs.”

Researchers at UNSW, Sydney’s Westmead Hospital, Imperial College (London) and the National Centre for Immunization Research studied more than 280 adults in 143 families in Sydney during the winter season of 2006 and 2007. The adults were randomly allocated masks when exposed to a sick child in the household.

MacIntyre said a drawback was participants’ low compliance, with less than half reporting having worn the masks often or always, said a UNSW release.

These findings were published in Emerging Infectious Diseases, the journal of the US Centre for Disease Control and Prevention.