Without claiming any knowledge of this particular case, the FDA has processes for accelerating approval for medication for which mass efficacy testing can only

Without claiming any knowledge of this particular case, the FDA has processes for accelerating approval for medication for which mass efficacy testing can only be done in the long-term, but testing for adverse side-effects is already complete. The recent approval of Alzheimer's medication[0] is one example of that. From a quick Google, it seems that Phase III trials are about comparing a new treatment to existing alternatives, rather than monitoring side-effects. Perhaps the testing simply can't be complete before 2023, since it involves checking long-term immunity? In this case, the FDA may have approved the vaccine because they are confident that the risk of negative side-effects is sufficiently small, and that the vaccine gives some benefit - even if testing hasn't established exactly how much. [0]: https://www.theguardian.com/commentisfree/2021/jun/28/alzheimers-drug-aducanumab-approval-dementia https://www.theguardian.com/commentisfree/2021/jun/28/alzhei...