There were human trials, but they skipped Longitudinal trials (long term effects) and they also didn't do challenge responses (exposing those people with the vaccine to COVID in a controlled manner), correct?
Normal vaccine trials is like normal software testing. Challenge testing is like running dangerous tests in production. Its faster at detecting a problem than normal tests, but ultimately not needed and can blow up badly. The argument for doing it during covid is that time was of the essence and its faster than normal testing procedures. Instead we opted for the safer slower normal testing procedure.
“Even after the vaccine is approved and licensed, regulatory agencies stay involved, continuing to monitor production; inspecting manufacturing facilities; and testing vaccines for potency, safety and purity.
The FDA also monitors adverse events that may occur related to receiving the vaccine, including through its Vaccine Adverse Event Reporting System and Phase 4 clinical trials—optional studies pharmaceutical companies may be required to perform after a vaccine is licensed to continue to monitor safety and effectiveness.” [0]
[0] https://www.jnj.com/innovation/the-5-stages-of-covid-19-vacc...