An inexpensive and widely available steroid is the first drug to show evidence of saving lives in patients severely sick with the coronavirus.

Doses of dexamethasone reduced deaths by a third in ventilated patients and a fifth in patients receiving just oxygen, according to a trial across hospitals in the U.K.

The results suggest that one death would be prevented for about every eight ventilated patients treated or roughly 25 patients who need oxygen alone, according to the findings published Tuesday.

The researchers behind the trial said it shows that the steroid should be immediately used for patients with severe cases of the virus.

“Dexamethasone is the first drug to be shown to improve survival in COVID-19,” Peter Horby, one of the chief investigators for the trial, said in a statement. “This is an extremely welcome result. The survival benefit is clear and large in those patients who are sick enough to require oxygen treatment, so dexamethasone should now become standard of care in these patients. Dexamethasone is inexpensive, on the shelf, and can be used immediately to save lives worldwide.”

No treatments or vaccines have been approved for use against the coronavirus, which has infected more than 8 million people and killed nearly 438,000.

In the U.S., researchers behind a widely cited model increased their death projections for the country. The news comes as many states see rises in their case numbers and hospitalizations after beginning to reopen.

The new forecast from the Institute for Health Metrics and Evaluation at the University of Washington predicts more than 200,000 deaths in the U.S. from the virus by Oct. 1. That’s up from its estimate of nearly 170,000 fatalities last week.