Cheap steroids can save the lives of patients who are critically ill with Covid-19, studies show.
The findings confirm the results of an earlier trial, which has already led to steroids being used widely for Covid patients in intensive care.The new results, published in JAMA, show eight lives would be saved for every 100 patients treated.
The researchers said the findings were impressive, but stressed steroids were not a coronavirus cure.
What progress are we making on treatments?
In June, the UK's Recovery trial found the first drug - a steroid called dexamethasone - that could save the lives of people with severe Covid.
The latest study brings together all clinical trials involving steroids on coronavirus patients around the world.
It confirms dexamethasone works and that another steroid, hydrocortisone, is equally effective.
"At the beginning of the year, at times it felt almost hopeless knowing that we had no specific treatments," said Prof Anthony Gordon, from Imperial College London.
"It was a very worrying time, yet less than six months later we've found clear, reliable evidence in high quality clinical trials of how we can tackle this devastating disease."The results on 1,703 critically ill patients showed:
40% died when given only standard treatment
32% died when given steroids
The studies were on only the sickest hospital patients. Most people recover having only experienced mild symptoms.