Although the timeline has been accelerated, the integrity of the trial and approval processes have remained. Scientists had a head start on developing the COVID-19 vaccine, using their experience from previous coronavirus vaccine efforts. Another way scientists preserved safety and saved time was by working on efforts simultaneously, rather than one after another like the traditional process. For example, COVID-19 vaccines were in Phase III clinical trials at the same time they were being manufactured. When it was proven safe and effective, the manufactured vaccines were deployed. If the vaccines don’t pass the approval process, which is verified by an independent committee of health experts, the unproven vaccines won’t be used.