A triple drug combination of antiviral medicines helped relieve symptoms in patients with mild to moderate COVID-19 infection and swiftly reduced the amount of virus in their bodies, according to results of a small trial in Hong Kong.

The trial, which involved 127 patients, compared those given the combination drug - made up of the HIV medicine lopinavir–ritonavir, the hepatitis drug ribavirin, and the multiple sclerosis treatment interferon beta - with a control group given just the HIV drug.

The findings, published in the Lancet medical journal, showed that on average, people who got the triple drug reached the point of no detectable virus five days earlier than those in the control group - at seven days versus 12 days.

"Our trial demonstrates that early treatment of mild to moderate COVID-19 with a triple combination of antiviral drugs may rapidly suppress the amount of virus in a patient's body, relieve symptoms, and reduce the risk to health-care workers," said Kwok-Yung Yuen, a professor at the University of Hong Kong who co-led the research.

He said the lower risk to health workers would be due to the combination drug's effect in reducing 'viral shedding' - which is when the virus is detectable and potentially transmissible.

In the trial, all patients received standard hospital care as needed, including ventilation support, dialysis support, antibiotics and corticosteroids.

Kowk-Yung Yuen said the findings were "encouraging", but that the triple drug's effect now needed to be tested in larger numbers of patients and in people with more severe COVID-19 illness.

Independent experts agreed that the findings were positive, but said larger and more detailed studies would be needed.

"This definitely justifies the consideration of adding interferon beta to the list of genuinely, evidence-based, promising treatments to be tested in further randomised trials," said Stephen Evans, a professor of pharmacoepidemiology at the London School of Hygiene & Tropical Medicine.

He said that long years of experience in treating the human immunodeficiency virus (HIV) that causes AIDS have shown that it is best treated with combinations of different drugs "and this could also be the case with COVID-19".