En español | In the race to make COVID-19 treatments and vaccines available to the public, a little-known tool at the U.S. Food and Drug Administration (FDA) is suddenly getting a lot of attention. It's called Emergency Use Authorization, or EUA for short, and it lets the FDA allow the use of unapproved medical products that can diagnose, treat or — in the case of vaccines — prevent life-threatening diseases during public health emergencies, such as the coronavirus pandemic.
Just this week, the FDA issued an EUA for Regeneron's monoclonal antibody cocktail treatment to help prevent patients with mild to moderate cases of COVID-19 from getting sicker. Pharmaceutical companies Pfizer/BioNTech are awaiting word on whether the agency will do the same for its coronavirus vaccine.
"You have these crises that require very fast action, so you need the ability to respond quickly,” says Joshua Sharfstein, M.D., vice dean for Public Health Practice at the Johns Hopkins Bloomberg School of Public Health and a former principal deputy commissioner at the FDA. “You may not have all the evidence you want, but the agency shows flexibility to do what makes sense.”
Here's what you need to know about the FDA's tool for fast-tracking much-needed medical products.
What's the difference between an EUA and regular FDA approval?
Time is a major one. The FDA's traditional approval process can take years, and that sort of time frame seems almost indefensible in the middle of a pandemic that's already claimed close to 260,000 lives in the U.S. alone.
As Francis Collins, M.D., director of the National Institutes of Health (NIH), explained in a recent AARP tele-town hall event, there are two notable differences between an EUA and a full FDA approval. One is the detail that the FDA requires in terms of manufacturing the medicine. “It's not quite as demanding for the Emergency Use Authorization,” he explains. The other difference has to do with the timetable.
"With an Emergency Use Authorization, FDA [requires] two months of follow-up on at least half the people in the trial who got the vaccine to see if there were any unexpected side effects. For a full authorization, you'd want … several more months,” Collins said. “To wait for that when there are people dying, and when we think this vaccine could save maybe hundreds of thousands of lives, doesn't seem like the right thing either."
It's important to note that the evidence standard can also be lower for EUAs compared with traditional FDA approval. In the case of a potential EUA, the FDA weighs the risks and benefits using what evidence it has. If certain criteria are met — for instance, there are no other already-approved alternatives — then it issues an EUA.
"The Emergency Use Authorization is still extremely rigorous,” Collins told AARP. “Let nobody try to tell you that this is cutting corners."
How is safety ensured when time is of the essence?
It varies with each type of product. With a coronavirus vaccine, for instance, “the FDA has set a pretty high standard for safety” that must be met before it receives an EUA, Sharfstein explains.
For instance, vaccine manufacturers must submit at least two months of safety data for tens of thousands of people who received the vaccine. The FDA will look for evidence of safety issues, including deaths, hospitalizations and other adverse events. In the name of transparency, that data will then be “shared publicly and with independent experts,” Sharfstein says. “If the evidence is strong and that's what we hear from the independent experts, it will be a vaccine that's worth taking."
And while two months of safety data may seem inadequate compared to the longer periods required of a standard FDA approval, that time frame isn't arbitrary. “Generally, most safety events occur in the first month or two after vaccination,” says Jesse Goodman, M.D., professor of medicine and infectious diseases at Georgetown University and former chief scientist at the FDA. “So, if all that data holds up and is confirmed by the FDA, that'll be good evidence of the safety of the vaccine."
What's more, after a vaccine is authorized or approved, both the FDA and the Centers for Disease Control and Prevention (CDC) continue to monitor for long-term safety concerns.
What concerns should consumers have about the effectiveness of a vaccine — or, for that matter, any treatment — that's developed so quickly?
Anyone who followed the FDA's handling of hydroxychloroquine — a medication that's used to prevent and treat malaria — could be forgiven for having concerns. In the early days of the pandemic, the FDA granted an EUA to use hydroxychloroquine as a treatment for COVID-19. But, as a report in an October issue of JAMA makes clear, the agency did so without describing the evidence underlying its decision. A little more than two months after the drug received FDA authorization, a number of studies reported that hydroxychloroquine was an ineffective treatment for COVID-19, and the FDA revoked its EUA.
"Most people believed the EUA of hydroxychloroquine was ill-founded and then the studies showed it didn't work,” Goodman says. But using an unapproved vaccine on healthy people requires a different standard than using an unapproved drug — or an approved drug for unapproved uses, which is also allowed under an EUA — to treat people with a life-threatening illness.
"A drug you're giving to someone who's sick, maybe critically ill, and there's a willingness to accept uncertainty,” Goodman points out. “A vaccine you're giving to someone who's well and may have other ways to reduce their risk of infection, like wearing a mask. What's been made very clear is that for a vaccine to be given to healthy people — even for emergency use — the FDA is going to insist on some strong data.”
Do therapies and diagnostics that receive EUAs eventually have to get official FDA approval?
EUAs aren't meant to be a substitute for traditional approvals. “In the end, it's not that different,” Sharfstein says. The companies developing the treatments and diagnostics “design their studies for approval, not just for [emergency use] authorization. There's not any real difference. It's a very high standard for authorization.”
The FDA, in its guidelines for the development and licensure of coronavirus vaccines, encourages drugmakers to pursue traditional approval in addition to authorization.