GlaxoSmithKline Relenza (zanamivir) should be stockpiled alongside Roche’s Tamiflu (oseltamivir) and used to prevent an outbreak of avian flu, researchers write in this week’s issue of The Lancet.

The authors, from universities in Hong Kong, Singapore, Kuala Lumpur and Korea, say the H5N1 strain of avian flu that is rampaging around Asia could prove catastrophic should human-to-human transmission become more efficient through viral mutation: influenza pandemics in the last century resulted in over 16 million deaths.

However, a vaccine against H5N1 is not likely to become available in the foreseeable future, putting the spotlight on antiviral drugs – particularly the neuraminidase inhibitors, Relenza and Tamiflu – as part of a bid to stem the severity and duration of symptoms. In fact, many governments – including those of Hong Kong, Thailand, Singapore, Malaysia and Korea - have already stockpiled Tamiflu at what the authors term “considerable expense.” But the call is out to generate similar supplies of Relenza, which “has fewer adverse reactions and a favourable resistance profile,” but has not been considered because of concerns that young children and others may not be able to use the inhalation device appropriately.

The researchers are also suggest Relenza and Tamiflu be evaluated as a combination therapy, with or without other agents, and call for manufacturing facilities to be established in Asia to prevent a delay in poorer nations obtaining a new vaccine or antiviral therapy to combat avian flu.