Emergency use authorization, does not require testing to the same degree as FDA approved. It must be tested on animals, pregnant animals (they use ferrets, for some reason their system is comparable to ours). Also these tests are run for years (7-10 yrs) before being tested on the humans that agree to be part of the research. I hope that clarifies it. A good example of not thoroughly testing was Thalidomide, given to pregnant women in the 60s to help with morning sickness. What happened was horrible and they pulled it off the market. Thalidomide - WikipediaI’m not sure that is what that means, actually. As far as I know, emergency use vaccines and “normal” vaccines go under the same testing. Whereas the bureaucratic processes which follow the testing are different.
Here is another one under drug for morning sickness that was not adequately tested: Drug for 'Morning Sickness' Is Suspected in Birth Defects - The Washington Post Bendectin -- sold abroad as Debendox-- Summary: One charge is that Merrell did no premarketing animal or clinical tests of safety for the unborn, even though women in the sensitive first trimester of pregnacy were the sole sales target. "It is true that no studies were done," Merrell's former medical research director, Raymond C. Pogge, said. Pogge, who invented Bendectin, made a deposition in Casa Grande, Ariz.
In essence, the Covid vaccine was not, has not been tested adequately.