The number of fully-vaccinated Iowans has exceeded 500,000 as of Thursday.Earlier in the week, the number of people who have been fully vaccinated within the state, which includes non-Iowa residents, already surpassed the milestone, but now the number of Iowa residents has as well.As of Thursday afternoon, the number of Iowa residents who have been fully vaccinated hit 504,976, which is over 20 percent of Iowans 16 and older.