Ohio STNA Certification - How long is it valid?

Once an NA has her Ohio STNA Certification (Ohio), how long is it good? Seems to me a person has to work so many hours in the first year, but then what?

I guess my REAL question is this: if a person obtains her STNA Ohio Certification but doesn't find a job as a nursing assitant until nearly a year later, does she have to retest again? Does she have to take the classes again?

Thanks for any info.