The study, helmed by an international team of drug researchers behind the "Together Trial", found a 51 per cent decrease in hospitalisation or emergency visits in patients who received a dose of the drug pegylated interferon lambda.
That was compared with a placebo group of more than 1010 people, with more than 930 patients randomly selected to receive the drug.
The trial was conducted between June 2021 and February last year, and early treatment with the drug was found to be effective across dominant variants of COVID-19, according to the study published in The New England Journal of Medicine.
The findings were particularly exciting after the World Health Organisation declared the pandemic far from over, Monash Institute of Pharmaceutical Sciences adjunct professor and senior trial investigator Craig Rayner said.
"As COVID continues to rage on, there is an urgent global need for new and accessible solutions to prevent death and improve health outcomes for all people affected by COVID-19," Dr Rayner said.
"We also found that among patients with a high viral load at baseline, those who received pegylated interferon lambda had lower viral loads by day seven than those who received placebo, thus slowing the progression of the disease and decreasing the likelihood of it escalating into something more serious."
The trial recruited predominantly vaccinated patients.
University of Sydney scientists have meanwhile discovered a protein that blocks SARS-CoV-2 infection and forms a natural protective barrier in the human body.
The naturally occurring protein, LRRC15, works by attaching itself to the virus, preventing it binding with more vulnerable cells and reducing the chance of infection.
The research opens up an entirely new area of immunology research around the receptor and offers a promising pathway to develop new drugs, the team behind the study said.
Professor Greg Neely, who led the study, said his team was one of the three internationally to independently to uncover this specific protein's interaction with COVID-19.
"For me, as an immunologist, the fact that there's this natural immune receptor that we didn't know about, that's lining our lungs and blocks and controls virus, that's crazy interesting," Prof Neely said.
The team hopes their discovery will help develop new antiviral and antifibrotic medicines to treat COVID-19, and other viruses where lung fibrosis occurs.
The Australian College of Nursing on Friday called for the government to support nurses to deliver COVID-19 vaccines in residential aged care and disability facilities.
The new incentive payment announced by the government to support general practices and community pharmacies to administer COVID-19 vaccines to local facilities did not extend sufficiently to nurses, chief executive Kylie Ward said.
WEEKLY VIRUS FIGURES:
* Victoria: 2941 cases, 52 deaths
* NSW: 6440 cases, 62 deaths
* Queensland: 3866 cases, 33 deaths
* SA: 1495 cases, 94 deaths