SYDNEY (XINHUA) - Biomedical researchers led by an Australian team are testing whether a nasal spray, generally used as a blood thinner, could also offer protection against Covid-19.

Scientists from the University of Melbourne and Monash University, in collaboration with Oxford University, believe the anticoagulant heparin can neutralise Covid-19 spike proteins, which is how the virus penetrates host cells and spreads the disease, according to an article published on Thursday (Dec 23) on the website of the University of Melbourne.

Heparin has many practical advantages being cheap, simple to administer and stable at room temperature.

The spray would be easy to use, with two puffs in each nostril, three times a day, said Professor Gary Anderson, the director of the Centre for Lung Health Research at the University of Melbourne.

As such, it would be ideal in addition to vaccines to protect vulnerable populations such as the elderly, pregnant women and people with weak immune systems and front-line health workers.

Explaining the drug's process, Prof Anderson said Covid-19 first infects cells in the nose by binding to heparan sulphate on the surface of nasal cells.

The spray has a very similar structure to heparan sulphate, "so it behaves as a decoy and can rapidly wrap around the virus' spike protein like a python", Prof Anderson said, adding that it worked on all known variants including Omicron.

"It is now essential that we test the actual effectiveness of heparin in the rigorously designed, double-blinded, placebo-controlled clinical trial as this will provide definitive evidence," he said.

The six-month heparin clinical trial will be held at the Northern Hospital in Melbourne, using an innovative monitoring and treatment platform that allows researchers to access and remotely treat patients within 24 hours of their diagnosis.

The six-month study is due to start in February 2022.