The first clinical trial in the United States of a possible coronavirus treatment is underway in Nebraska and is expected to include 400 patients at 50 locations around the world.

Half of the patients in the international study will receive the antiviral medicine remdesivir while the other half will receive a placebo.

Several other studies, including one looking at the same drug, are already underway internationally.

Researchers at the University of Queensland in Australia said they were days away from testing a new vaccine for coronavirus on animals while other scientists in Australia developed a lab-grown version of the disease.

Dr Andre Kalil, who will oversee the study at the University of Nebraska Medical Centre, said the clinical trial was developed quickly in response to the virus outbreak that originated in China.

Patients who are hospitalized with the novel coronavirus COVID-19 will be eligible to join the trial if they have at least moderate symptoms.