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Understanding Emergency Use Authorization and Full Licensure of COVID-19 Vaccines

Americans who had been waiting for full licensure of COVID-19 vaccines are urged to get vaccinated. On August 23, 2021, the Food and Drug Administration (FDA) approved the first COVID-19 vaccine in the United States. The Pfizer-BioNTech COVID-19 vaccine is approved for ages 5 and older to help prevent COVID-19 disease. Moderna soon followed, receiving FDA approval on January 31, 2022. That COVID-19 vaccine is available to individuals 6 months of age and older.

The process of receiving emergency use authorization (EUA) and full FDA authorization, or full licensure, is a rigorous process. Andrew Pavia, MD, chief of the Division of Pediatric Infectious Diseases at University of Utah Health, explains how the process works and why the vaccines can be trusted.

Emergency Use Authorization

On December 11, 2020, the Pfizer-BioNTech COVID-19 vaccine received EUA based on safety and efficacy data from a clinical trial that involved more than 40,000 participants. The results from the clinical trial found the vaccine was 91% effective in preventing COVID-19 infection.

"People understandably put a lot of attention on the fact that COVID-19 vaccines were under EUA, but that was not for safety or efficacy reasons," Pavia says. "It's for regulatory reasons."

EUAs can be used during public health emergencies. The FDA determines whether a "medical product" is effective in preventing, diagnosing, or treating a disease and outweighs the known and potential risks of the product. Based on available data from Pfizer-BioNTech, the FDA determined they "provided clear evidence that its vaccine may be effective in preventing COVID-19."

Full Licensure

The regulatory process of receiving full licensure by the FDA is thorough and takes time. According to Pavia, when there is no public health emergency, it could take between eight months to a year from submission to full licensure. It took nine months for the Pfizer-BioNTech COVID-19 vaccine, which Pavia says is impressive but not out of the ordinary. "It just meant a lot of FDA officials worked nights and weekends to do the paperwork faster," he says. "There were no shortcuts taken and no steps skipped."

For Pfizer-BioNTech to receive full licensure of its COVID-19 vaccine, the FDA reviewed 340,000 pages of information. This included very specific, mandated requirements such as additional safety data, manufacturing capacity, inspection of plants and equipment, paperwork filing, etc.

"With full licensure, questions about the safety and efficacy of the vaccine should be answered now," Pavia says. "It's gone through every step that any vaccine would go through, with over 350 million doses given to more than 200 million Americans. It's now one of the most studied vaccines."

The FDA and Centers for Disease Control and Prevention have robust systems in place that continue to monitor the safety of COVID-19 vaccines.

Johnson & Johnson Vaccine

The Johnson & Johnson COVID-19 vaccine is available under EUA after an extensive review of safety and efficacy data from large clinical trials, with more than 30,000 participants. The J&J COVID-19 vaccine is available for individuals 18 years of age and older. In most situations, the CDC prefers the Pfizer-BioNTech or Moderna COVID-19 vaccines over the J&J COVID-19 vaccine due to the risk of adverse events. 

COVID-19 Vaccines for Children

Children aged 6 months and older can now get a COVID-19 vaccine and booster dose. The Pfizer-BioNTech COVID-19 vaccine is available for children ages 5 years and older.


This information was accurate at the time of publication. Due to the changing nature of the COVID-19 pandemic, some information may have changed since the original publication date.