The Food and Drug Administration on Friday issued an emergency-use authorization for remdesivir in a bid to help patients get quicker access to the first antiviral to show promise against Covid-19 infection.

The authorization comes two days after data from a government trial suggested the experimental drug could help patients recover faster and might reduce death rates compared with a placebo. The nation’s top infectious disease doctor, Anthony Fauci, said the results make remdesivir the new standard of care as researchers continue to develop more effective options.

But he also cautioned that, while the results were encouraging, they represented an early step toward finding effective coronavirus treatments — much as the drug AZT represented the first hope for AIDS patients in the 1980s, but was later supplanted by much more effective combination therapies.

An emergency-use authorization is not a full approval — the drug must undergo further review — but it allows doctors to use remdesivir outside clinical trials during the pandemic. FDA has issued emergency authorizations for a range of Covid-19 tests as well as for hydroxychloroquine, a malaria medicine with limited evidence suggesting it can fight the coronavirus. President Donald Trump has called remdesivir a “building block” in progress toward fighting the coronavirus.

The EUA allows the drug to be administered to patients with confirmed or suspected coronavirus infections.

“The statutory standard for EUA is very weak,” said Holly Fernandez Lynch, a medical ethics professor at the Perelman School of Medicine at the University of Pennsylvania. “If it was met for [hydroxychloroquine], which was questionable to be honest, it was clearly met here. It’s just ‘may be effective’ based on available evidence.”

Fernandez Lynch said she was “a little surprised” that the EUA applied to patients whose coronavirus diagnosis had not been confirmed by testing.

The full findings from the federal trial of the drug, sponsored by the National Institute of Allergy and Infectious Diseases, have not been publicly released.

Gilead has said it will donate the first 1.5 million doses of remdesivir, which should be enough for about 140,000 Covid-19 patients. Questions remain on how much remdesivir will eventually cost.

Democratic Reps. Lloyd Doggett of Texas and Rosa DeLauro of Connecticut recently questioned Health and Human Services Secretary Alex Azar on how much the federal government has spent on the research and development of remdesivir.