It sounds like the area had a number of large summer events -- sounds like stuff like a county fair and large concerts? If vaccination offers 95% protection in the course of typical daily life, it's not that surprising that one in twenty people will get infected after a series of large public gatherings. It's like everyone looked at that 95% effectiveness number and decided that it's 100% bulletproof protection. The fact that so few were hospitalized (and only one of those hospitalized was vaccinated) is a positive sign.