Influenza vaccination rates in Iowa beat out the national average during the past flu season. But state public health officials say that’s not enough to ensure Iowans stay healthy this winter.According to the federal Centers for Disease Control and Prevention, 43 percent of adults in Iowa received an influenza vaccine during the 2017-18 flu season, six percent higher than the national average.But that’s a drop from past flu vaccine rates among adults in Iowa, data shows.