What Is an Emergency Use Authorization (EUA)?
Key takeaways:
An emergency use authorization (EUA) allows for unapproved tests, vaccines, and treatments to be used during a public health emergency.
The FDA approves EUAs based on the best available evidence. This may include interim or final clinical trial data for treatments and vaccines.
Vaccines, treatments, and tests available through an EUA can’t be used after the public health emergency is declared over.
The term “emergency use authorization” (EUA) has become well known over the last 2 years. That’s because many of the vaccines, tests, and treatments for COVID-19 became available through this pathway. But did you know that EUAs have been around since the early 2000s?
In fact, they were created in 2003 to protect the U.S. against bioterrorism attacks, like anthrax, smallpox, and Ebola. Since then, they’ve been used for emergencies like the H1N1 swine flu in 2009, Ebola in 2014, and Zika virus in 2016. Starting in 2020, they’ve been used for COVID-19.
Read on to learn more about EUAs, when they’re used, and how they’re different from full FDA approval.
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What is an emergency use authorization?
During public health emergencies, there may be times when treatments, tests, and vaccines are needed but aren’t available. This may be because the disease causing the emergency has never been seen before. In this case, these products need to be developed quickly to protect public health. But the full FDA approval process may be too slow.
An emergency use authorization (EUA) allows for unapproved products (e.g., treatments and vaccines) to be used temporarily during a public health emergency. Compared to the full FDA approval process, EUAs allow the public to access these products faster when they’re most needed.
When can an EUA be used?
There are several types of emergencies that can affect the U.S. Public health emergencies are one example. A public health emergency can be declared by the secretary of the Department of Health and Human Services (HHS). But this act alone doesn’t allow EUAs to be used.
Once the HHS secretary declares a public health emergency, they also decide if the situation warrants using EUAs. If it does, the FDA is given authority to issue EUAs.
The FDA is able to issue EUAs for products addressing the emergency if no adequate, approved, and available alternatives exist. These products are intended to prevent, treat, or diagnose serious or life-threatening conditions.
How does an EUA work?
First, the FDA develops guidance documents. These help companies develop products for potential authorization. These documents also outline the FDA’s safety and effectiveness expectations. For example, vaccines may require minimum efficacy and tests may need to have a certain level of accuracy.
Vaccines, tests, and treatments need to have supporting data for the FDA to review as part of the EUA. For treatments and vaccines, this requires clinical trials to study benefits and risks. Tests need to be validated to make sure they can accurately detect infections. Medical devices also need to meet standards to be granted EUA.
Once these products are developed and tested, the company may choose to submit an EUA request. The FDA then reviews the submitted information and decides whether the product’s known and potential benefits outweigh its known and potential risks. If they do, the FDA may authorize the product.
The EUA usually includes information about how the product is authorized to be used. This may include how to use it, who can use it, and what it’s used for. Other important information may include risks, warnings, and side effects.
How long does an EUA last?
An EUA lasts only as long as the public health emergency and EUA declarations are in effect. Once the EUA is terminated, authorized products can no longer be used. However, some companies may pursue and achieve full FDA approval for authorized products. That means the products can continue being used, even if the EUAs are terminated.
Examples of authorized products that became FDA-approved for COVID-19 include Pfizer’s COVID-19 vaccine and remdesivir (Veklury).
Additionally, EUAs can be changed or revoked at any time. For instance, treatments that are found to no longer be effective may have their EUA revoked. And sometimes, an EUA may be changed to reflect new uses, age groups, or risks.
An example of an EUA that’s been revoked is bamlanivimab for COVID-19 treatment. It was revoked because of resistance concerns from new virus variants (mutations) that would make the medication less effective.
An example of an EUA that has been changed over time is Pfizer’s COVID-19 vaccine. While the vaccine is FDA-approved for people at least 16 years old, its EUA is still in place for people ages 12 to 15 years old. The updated EUA allows the younger age group to receive the vaccine, even though it’s not approved for this group yet. The EUA now also includes booster dose information.
What is the difference between an EUA and full FDA approval?
The FDA approves EUAs based on the best scientific evidence available at the time. This may include interim or final phase 3 clinical trial data. Phase 3 trials are the last step before a company can apply for approval.
As mentioned above, the FDA uses this evidence to determine if the known and potential benefits outweigh the known and potential risks. Remember: Not every EUA gets approved. The product needs to show that it meets the FDA’s outlined EUA criteria first.
For example, the COVID-19 vaccines are recommended to have at least 50% efficacy against infection. And at least half of the phase 3 clinical trial participants need to be followed for at least 2 months to monitor for safety issues. This is because most side effects tend to happen during this time.
But when a company applies for full FDA approval, additional information is required. For vaccines, phase 3 trial participants need to be followed for longer — at least 6 months. The pharmaceutical company also needs to provide additional clinical and manufacturing information. And the facilities manufacturing the vaccines need to be inspected, too.
Both the EUA and full approval of a product may involve expert advisory committees that help guide the FDA on their decision. The FDA makes the final call, but it usually follows the committee’s recommendation.
Once fully FDA-approved, a product can be used off-label by healthcare providers based on their clinical judgment. This means that it can be used in a way that’s not approved by the FDA. Conversely, authorized products should be used only in the way that’s been authorized by the FDA.
The bottom line
During a public health emergency, the standard FDA approval process may slow down necessary treatments, vaccines, and tests from reaching the public. EUAs may be issued to help meet this need faster.
The FDA approves EUAs based on the best available evidence. It uses this evidence to determine if the known and potential benefits outweigh the known and potential risks of the product. But EUAs don’t last forever: They can be approved, changed, or revoked at any time.
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References
Food and Drug Administration. (2018). Step 3: Clinical Research.
Food and Drug Administration. (2020). Development and Licensure of Vaccines to Prevent COVID-19; Guidance for Industry.
Food and Drug Administration. (2020). Emergency Use Authorization for Vaccines Explained.
Food and Drug Administration. (2020). Policy for Coronavirus Disease-2019 Tests During the Public Health Emergency (Revised).
Food and Drug Administration. (2021). Comirnaty Package Insert.
Food and Drug Administration. (2021). Coronavirus Treatment Acceleration Program (CTAP).
Food and Drug Administration. (2021). COVID-19-Related Guidance Documents for Industry, FDA Staff, and Other Stakeholders.
Food and Drug Administration. (2021). Emergency Use Authorization.
Food and Drug Administration. (2021). Fact Sheet for Healthcare Providers Administering Vaccine (Vaccination Providers): Emergency Use Authorization (EUA) for the Moderna COVID-19 Vaccine.
Food and Drug Administration. (2021). Fact Sheet for Healthcare Providers Administering Vaccine (Vaccination Providers): Emergency Use Authorization (EUA) of the Pfizer-BioNTech COVID-19 Vaccine.
Food and Drug Administration. (2021). FDA Approves First COVID-19 Vaccine.
Food and Drug Administration. (2021). Historical Information about Device Emergency Use Authorizations.
Food and Drug Administration. (2021). Revocation Letter Bamlanivimab.
Food and Drug Administration. (2021). Summary of Process for EUA Issuance.
U.S. Government Publishing Office. (2003). Project BioShield Act of 2003.
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