In the first episode of The Flash (2014), Barry's struck by lightning, some chemicals fall on him, and he enters a coma for 9 months. This happens when the S.T.A.R. Labs particle accelerator is turned on for the first time. 9 months later, he wakes up and has powers. He then starts fighting crime, especially other meta-humans who were created by the same particle accelerator accident. However, this is all 9 months after the accident, where were the other meta-humans during those 9 months? The S.T.A.R. Labs people make it sound like they hadn't seen any meta-humans active during the 9 months Barry was out.
Did all people granted powers by the particle accelerator accident also fall into comas? Why weren't they active heroes/villains during the 9 month gap?