Last year, the US FDA issued an "Emergency Use Authorization" for Pfizer-BioNTech vaccine for Covid-19.

I read the wikipedia page on what that means, and it seems as though this can be issued under very lax conditions (e.g. human use after animal-only experiments). On the other hand, I know that the Pfizer-BioNTech vaccine passed "Phase III" trials.

What is missing, therefore, for the vaccine to qualify for "regular" FDA approval? Is it a longer period of time for evaluating the possibility of unexpected mid/long-term detrimental effects in vaccinated patients? Are there additional missing experiments/trials? Or perhaps just administrative procedures?

PS - I've gotten (both doses of) this vaccine already, so please don't mistake this question to about whether or not to get vaccinated.

  • Basically the threshold of evidence required for approval by the FDA for emergency use is lower than what they would otherwise require for such an approval. This authorization is contingent and does not represent standard "approval". Section 564 of the Federal Food, Drug, and Cosmetic Act details the procedures and requirements the FDA must use to grant EUA. Mar 24, 2021 at 1:51

1 Answer 1


Well, it turns out I was wrong: The Pfizer-BioNTech vaccine's Phase 3 trials have not been completed: US Government listing of the trials. They will not be over before 2023...

The FDA approval requirements/process is summarized as follows:

  1. An Investigational New Drug application
  2. Pre-licensure vaccine clinical trials
  3. A Biologics License Application (BLA)
  4. Inspection of the manufacturing facility
  5. Presentation of findings to FDA’s Vaccines and Related Biological Products Advisory Committee (VRBPAC)
  6. Usability testing of product labeling

it seems the vaccine is (as of March 2021) in step 2 of the above. Although it theoretically may have already cleared steps (3.), (4.) and (6.) independently. Perhaps others can shed light on this point.

  • So, there is some reasonable degree of uncertainty as to the safety of the vaccine at least until Phase 3 trials have been completed, in the eyes of the FDA?
    – Don Slowik
    Jul 24, 2021 at 17:33
  • How reasonable the delay, and its importance, is discussed well here nytimes.com/2021/07/21/briefing/…
    – Don Slowik
    Jul 24, 2021 at 18:00
  • @DonSlowik thy nytimes article is behind a paywall / signup wall. But regarding you question if there is some reasonable degree of uncertainty as to the safety of the vaccine: The safety of the mRNA vaccines is bad. On first december 2020 scientists have asked the EMA to stop the shots and evaluate the safety before continuing the shots. The Vaccine Adverse Event Reporting System has plenty of safety signals. Jessica Rose has analyzed vaers and confirms there are safety concerns.
    – surfmuggle
    Dec 26, 2022 at 12:09
  • Jessica wrote on jessicar.substack.com that there are fake accounts from imposters. Since there is also jessica5b3.substack.com. i am not 100% certain which url is the real deal. On the first impression all three urls seem genuine.
    – surfmuggle
    Dec 26, 2022 at 12:24

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