A cheap and widely available drug can help save the lives of patients seriously ill with coronavirus, the BBC reports.

The low-dose steroid treatment dexamethasone is a major breakthrough in the fight against the deadly virus, UK experts say.

The drug is part of the world's biggest trial testing existing treatments to see if they also work for coronavirus.

It cut the risk of death by a third for patients on ventilators. For those on oxygen, it cut deaths by a fifth.

Had the drug had been used to treat patients in the UK from the start of the pandemic, up to 5,000 lives could have been saved, researchers say.

And it could be of huge benefit in poorer countries with high numbers of Covid-19 patients.

About 19 out of 20 patients with coronavirus recover without being admitted to hospital. Of those who are admitted to hospital, most also recover, but some may need oxygen or mechanical ventilation. These are the high-risk patients whom dexamethasone appears to help.

The drug is already used to reduce inflammation in a range of other conditions, and it appears that it helps stop some of the damage that can happen when the body's immune system goes into overdrive as it tries to fight off coronavirus.