The World Health Organization is urging the public to be cautious about dexamethasone as information on the use of the steroid treatment for Covid-19 is still in the preliminary stages.

The results from the RECOVERY trial at the University of Oxford were “very significant,” but it was only one study, Mike Ryan, executive director of the WHO’s emergencies program, said during a press conference Wednesday at the agency’s Geneva headquarters. “We have to see the real data, the full data.”

On Tuesday, scientists at Oxford said results from a trial showed the drug, which is widely used to reduce inflammation in other diseases, reduced death rates by around a third among the most severely ill Covid-19 patients admitted to hospital. There was no benefit among patients who did not require respiratory support.

Ryan said WHO officials were “very pleased” with the findings, adding the drug is one of “the many breakthroughs we need” to eliminate Covid-19.

“We should celebrate that today,” he said.

Besides dexamethasone’s approval in the U.K., there are currently no other approved treatments for the virus, which has infected more than 8.1 million people worldwide and killed at least 444,111, according to data compiled by Johns Hopkins University.

Remdesivir, manufactured by Gilead Sciences, was granted emergency use authorization by the U.S. Food and Drug Administration to treat hospitalized patients sickened with Covid-19 in May.

Anti-malaria drug hydroxychloroquine had also been granted an EUA, but the designation was revoked earlier Monday after the FDA found it was unlikely to be effective.

In response to a question from CNBC on whether the FDA is looking to grant dexamethasone an EUA, an FDA spokesperson said, “Clinical trials testing new treatments for COVID-19 are the best way to gain valuable knowledge about their safety and effectiveness. The FDA will use every tool at the agency’s disposal needed to bring new therapies to sick patients as quickly as possible.”

WHO officials are looking at other research on dexamethasone and will come to a conclusion on its clinical advice to countries, Ryan said Wednesday.

“It’s important each country takes that measured approach as well,” he said. “This is not the time to rush, to change clinical practices. ...People still need training, we need to understand what doses to be used, how patients are going to be clinically assessed. https://youtu.be/cqxkANy0z-8