Researchers at Oxford University in the UK announced last week that a low-dose steroid treatment—which costs about $6 per dose and is widely available—can reduce the risk of death by one-third for patients on ventilators, and by one-fifth for those on oxygen.

"It's a major breakthrough," the chief investigator, Professor of Emerging Infectious Diseases Peter Horby, told the BBC. "This is the only drug so far that has been shown to reduce mortality—and it reduces it significantly."

Doctors typically use the drug, called dexamethasone, to reduce inflammation in their patients. It is an effective treatment for a wide range of conditions, including asthma, arthritis, and even some skin problems. It seems to help coronavirus patients by reducing the damage of cytokine storms, a condition where the immune system goes into overdrive and attacks healthy tissue as it tries to fight the virus.

"It is fantastic that the first treatment demonstrated to reduce mortality is one that is instantly available and affordable worldwide," wrote Prof. Martin Landry, another lead researcher, in a press release.

Called the RECOVERY trial (Randomized Evaluation of COVid-19 thERapY), the study, which involved 175 hospitals across the whole of the UK, found no outstanding adverse events from the 10-day treatment given to 2104 patients in the randomized trial of over 6400 infected patients, investigators said.